'To lose one's head' definitions:

Definition of 'To lose one's head'

From: GCIDE

Head \Head\ (h[e^]d), n. [OE. hed, heved, heaved, AS. he['a]fod; akin to D. hoofd, OHG. houbit, G. haupt, Icel. h["o]fu[eth], Sw. hufvud, Dan. hoved, Goth. haubi[thorn]. The word does not correspond regularly to L. caput head (cf. E. Chief, Cadet, Capital), and its origin is unknown.]
1. The anterior or superior part of an animal, containing the brain, or chief ganglia of the nervous system, the mouth, and in the higher animals, the chief sensory organs; poll; cephalon. [1913 Webster]
2. The uppermost, foremost, or most important part of an inanimate object; such a part as may be considered to resemble the head of an animal; often, also, the larger, thicker, or heavier part or extremity, in distinction from the smaller or thinner part, or from the point or edge; as, the head of a cane, a nail, a spear, an ax, a mast, a sail, a ship; that which covers and closes the top or the end of a hollow vessel; as, the head of a cask or a steam boiler. [1913 Webster]
3. The place where the head should go; as, the head of a bed, of a grave, etc.; the head of a carriage, that is, the hood which covers the head. [1913 Webster]
4. The most prominent or important member of any organized body; the chief; the leader; as, the head of a college, a school, a church, a state, and the like. "Their princes and heads." --Robynson (More's Utopia). [1913 Webster]
The heads of the chief sects of philosophy. --Tillotson. [1913 Webster]
Your head I him appoint. --Milton. [1913 Webster]
5. The place or honor, or of command; the most important or foremost position; the front; as, the head of the table; the head of a column of soldiers. [1913 Webster]
An army of fourscore thousand troops, with the duke of Marlborough at the head of them. --Addison. [1913 Webster]
6. Each one among many; an individual; -- often used in a plural sense; as, a thousand head of cattle. [1913 Webster]
It there be six millions of people, there are about four acres for every head. --Graunt. [1913 Webster]
7. The seat of the intellect; the brain; the understanding; the mental faculties; as, a good head, that is, a good mind; it never entered his head, it did not occur to him; of his own head, of his own thought or will. [1913 Webster]
Men who had lost both head and heart. --Macaulay. [1913 Webster]
8. The source, fountain, spring, or beginning, as of a stream or river; as, the head of the Nile; hence, the altitude of the source, or the height of the surface, as of water, above a given place, as above an orifice at which it issues, and the pressure resulting from the height or from motion; sometimes also, the quantity in reserve; as, a mill or reservoir has a good head of water, or ten feet head; also, that part of a gulf or bay most remote from the outlet or the sea. [1913 Webster]
9. A headland; a promontory; as, Gay Head. --Shak. [1913 Webster]
10. A separate part, or topic, of a discourse; a theme to be expanded; a subdivision; as, the heads of a sermon. [1913 Webster]
11. Culminating point or crisis; hence, strength; force; height. [1913 Webster]
Ere foul sin, gathering head, shall break into corruption. --Shak. [1913 Webster]
The indisposition which has long hung upon me, is at last grown to such a head, that it must quickly make an end of me or of itself. --Addison. [1913 Webster]
12. Power; armed force. [1913 Webster]
My lord, my lord, the French have gathered head. --Shak. [1913 Webster]
13. A headdress; a covering of the head; as, a laced head; a head of hair. --Swift. [1913 Webster]
14. An ear of wheat, barley, or of one of the other small cereals. [1913 Webster]
15. (Bot.) (a) A dense cluster of flowers, as in clover, daisies, thistles; a capitulum. (b) A dense, compact mass of leaves, as in a cabbage or a lettuce plant. [1913 Webster]
16. The antlers of a deer. [1913 Webster]
17. A rounded mass of foam which rises on a pot of beer or other effervescing liquor. --Mortimer. [1913 Webster]
18. pl. Tiles laid at the eaves of a house. --Knight. [1913 Webster]
Note: Head is often used adjectively or in self-explaining combinations; as, head gear or headgear, head rest. Cf. Head, a. [1913 Webster]
A buck of the first head, a male fallow deer in its fifth year, when it attains its complete set of antlers. --Shak.
By the head. (Naut.) See under By.
Elevator head, Feed head, etc. See under Elevator, Feed, etc.
From head to foot, through the whole length of a man; completely; throughout. "Arm me, audacity, from head to foot." --Shak.
Head and ears, with the whole person; deeply; completely; as, he was head and ears in debt or in trouble. [Colloq.]
Head fast. (Naut.) See 5th Fast.
Head kidney (Anat.), the most anterior of the three pairs of embryonic renal organs developed in most vertebrates; the pronephros.
Head money, a capitation tax; a poll tax. --Milton.
Head pence, a poll tax. [Obs.]
Head sea, a sea that meets the head of a vessel or rolls against her course.
Head and shoulders. (a) By force; violently; as, to drag one, head and shoulders. "They bring in every figure of speech, head and shoulders." --Felton. (b) By the height of the head and shoulders; hence, by a great degree or space; by far; much; as, he is head and shoulders above them.
Heads or tails or Head or tail, this side or that side; this thing or that; -- a phrase used in throwing a coin to decide a choice, question, or stake, head being the side of the coin bearing the effigy or principal figure (or, in case there is no head or face on either side, that side which has the date on it), and tail the other side.
Neither head nor tail, neither beginning nor end; neither this thing nor that; nothing distinct or definite; -- a phrase used in speaking of what is indefinite or confused; as, they made neither head nor tail of the matter. [Colloq.]
Head wind, a wind that blows in a direction opposite the vessel's course.
off the top of my head, from quick recollection, or as an approximation; without research or calculation; -- a phrase used when giving quick and approximate answers to questions, to indicate that a response is not necessarily accurate.
Out of one's own head, according to one's own idea; without advice or co["o]peration of another.
Over the head of, beyond the comprehension of. --M. Arnold.
to go over the head of (a person), to appeal to a person superior to (a person) in line of command.
To be out of one's head, to be temporarily insane.
To come or draw to a head. See under Come, Draw.
To give (one) the head, or To give head, to let go, or to give up, control; to free from restraint; to give license. "He gave his able horse the head." --Shak. "He has so long given his unruly passions their head." --South.
To his head, before his face. "An uncivil answer from a son to a father, from an obliged person to a benefactor, is a greater indecency than if an enemy should storm his house or revile him to his head." --Jer. Taylor.
To lay heads together, to consult; to conspire.
To lose one's head, to lose presence of mind.
To make head, or To make head against, to resist with success; to advance.
To show one's head, to appear. --Shak.
To turn head, to turn the face or front. "The ravishers turn head, the fight renews." --Dryden. [1913 Webster]

Definition of 'To lose one's head'

From: GCIDE

Lose \Lose\ (l[=oo]z), v. t. [imp. & p. p. Lost (l[o^]st; 115) p. pr. & vb. n. Losing (l[=oo]z"[i^]ng).] [OE. losien to loose, be lost, lose, AS. losian to become loose; akin to OE. leosen to lose, p. p. loren, lorn, AS. le['i]san, p. p. loren (in comp.), D. verliezen, G. verlieren, Dan. forlise, Sw. f["o]rlisa, f["o]rlora, Goth. fraliusan, also to E. loose, a & v., L. luere to loose, Gr. ly`ein, Skr. l[=u] to cut. [root]127. Cf. Analysis, Palsy, Solve, Forlorn, Leasing, Loose, Loss.] [1913 Webster]
1. To part with unintentionally or unwillingly, as by accident, misfortune, negligence, penalty, forfeit, etc.; to be deprived of; as, to lose money from one's purse or pocket, or in business or gaming; to lose an arm or a leg by amputation; to lose men in battle. [1913 Webster]
Fair Venus wept the sad disaster Of having lost her favorite dove. --Prior. [1913 Webster]
2. To cease to have; to possess no longer; to suffer diminution of; as, to lose one's relish for anything; to lose one's health. [1913 Webster]
If the salt hath lost his savor, wherewith shall it be salted? --Matt. v. 13. [1913 Webster]
3. Not to employ; to employ ineffectually; to throw away; to waste; to squander; as, to lose a day; to lose the benefits of instruction. [1913 Webster]
The unhappy have but hours, and these they lose. --Dryden. [1913 Webster]
4. To wander from; to miss, so as not to be able to and; to go astray from; as, to lose one's way. [1913 Webster]
He hath lost his fellows. --Shak [1913 Webster]
5. To ruin; to destroy; as destroy; as, the ship was lost on the ledge. [1913 Webster]
The woman that deliberates is lost. --Addison. [1913 Webster]
6. To be deprived of the view of; to cease to see or know the whereabouts of; as, he lost his companion in the crowd. [1913 Webster]
Like following life thro' creatures you dissect, You lose it in the moment you detect. --Pope. [1913 Webster]
7. To fail to obtain or enjoy; to fail to gain or win; hence, to fail to catch with the mind or senses; to miss; as, I lost a part of what he said. [1913 Webster]
He shall in no wise lose his reward. --Matt. x. 42. [1913 Webster]
I fought the battle bravely which I lost, And lost it but to Macedonians. --Dryden. [1913 Webster]
8. To cause to part with; to deprive of. [R.] [1913 Webster]
How should you go about to lose him a wife he loves with so much passion? --Sir W. Temple. [1913 Webster]
9. To prevent from gaining or obtaining. [1913 Webster]
O false heart! thou hadst almost betrayed me to eternal flames, and lost me this glory. --Baxter. [1913 Webster]
To lose ground, to fall behind; to suffer gradual loss or disadvantage.
To lose heart, to lose courage; to become timid. "The mutineers lost heart." --Macaulay.
To lose one's head, to be thrown off one's balance; to lose the use of one's good sense or judgment, through fear, anger, or other emotion. [1913 Webster]
In the excitement of such a discovery, many scholars lost their heads. --Whitney.
To lose one's self. (a) To forget or mistake the bearing of surrounding objects; as, to lose one's self in a great city. (b) To have the perceptive and rational power temporarily suspended; as, we lose ourselves in sleep.
To lose sight of. (a) To cease to see; as, to lose sight of the land. (b) To overlook; to forget; to fail to perceive; as, he lost sight of the issue. [1913 Webster]