'To do one's diligence' definitions:

Definition of 'To do one's diligence'

From: GCIDE

Diligence \Dil"i*gence\, n. [F. diligence, L. diligentia.]
1. The quality of being diligent; carefulness; careful attention; -- the opposite of negligence. [1913 Webster]
2. Interested and persevering application; devoted and painstaking effort to accomplish what is undertaken; assiduity in service. [1913 Webster]
That which ordinary men are fit for, I am qualified in; and the best of me is diligence. --Shak. [1913 Webster]
3. (Scots Law) Process by which persons, lands, or effects are seized for debt; process for enforcing the attendance of witnesses or the production of writings. [1913 Webster]
To do one's diligence, give diligence, use diligence, to exert one's self; to make interested and earnest endeavor. [1913 Webster]
And each of them doth all his diligence To do unto the fest['e] reverence. --Chaucer.
Syn: Attention; industry; assiduity; sedulousness; earnestness; constancy; heed; heedfulness; care; caution. -- Diligence, Industry. Industry has the wider sense of the two, implying an habitual devotion to labor for some valuable end, as knowledge, property, etc. Diligence denotes earnest application to some specific object or pursuit, which more or less directly has a strong hold on one's interests or feelings. A man may be diligent for a time, or in seeking some favorite end, without meriting the title of industrious. Such was the case with Fox, while Burke was eminent not only for diligence, but industry; he was always at work, and always looking out for some new field of mental effort. [1913 Webster]
The sweat of industry would dry and die, But for the end it works to. --Shak. [1913 Webster]
Diligence and accuracy are the only merits which an historical writer ascribe to himself. --Gibbon. [1913 Webster]

Definition of 'To do one's diligence'

From: GCIDE

do \do\ (d[=oo]), v. t. or auxiliary. [imp. did (d[i^]d); p. p. done (d[u^]n); p. pr. & vb. n. Doing (d[=oo]"[i^]ng). This verb, when transitive, is formed in the indicative, present tense, thus: I do, thou doest (d[=oo]"[e^]st) or dost (d[u^]st), he does (d[u^]z), doeth (d[=oo]"[e^]th), or doth (d[u^]th); when auxiliary, the second person is, thou dost. As an independent verb, dost is obsolete or rare, except in poetry. "What dost thou in this world?" --Milton. The form doeth is a verb unlimited, doth, formerly so used, now being the auxiliary form. The second pers, sing., imperfect tense, is didst (d[i^]dst), formerly didest (d[i^]d"[e^]st).] [AS. d[=o]n; akin to D. doen, OS. duan, OHG. tuon, G. thun, Lith. deti, OSlav. d[=e]ti, OIr. d['e]nim I do, Gr. tiqe`nai to put, Skr. dh[=a], and to E. suffix -dom, and prob. to L. facere to do, E. fact, and perh. to L. -dere in some compounds, as addere to add, credere to trust. [root]65. Cf. Deed, Deem, Doom, Fact, Creed, Theme.]
1. To place; to put. [Obs.] --Tale of a Usurer (about 1330). [1913 Webster]
2. To cause; to make; -- with an infinitive. [Obs.] [1913 Webster]
My lord Abbot of Westminster did do shewe to me late certain evidences. --W. Caxton. [1913 Webster]
I shall . . . your cloister do make. --Piers Plowman. [1913 Webster]
A fatal plague which many did to die. --Spenser. [1913 Webster]
We do you to wit [i. e., We make you to know] of the grace of God bestowed on the churches of Macedonia. --2 Cor. viii. 1.
Note: We have lost the idiom shown by the citations (do used like the French faire or laisser), in which the verb in the infinitive apparently, but not really, has a passive signification, i. e., cause . . . to be made. [1913 Webster]
3. To bring about; to produce, as an effect or result; to effect; to achieve. [1913 Webster]
The neglecting it may do much danger. --Shak. [1913 Webster]
He waved indifferently 'twixt doing them neither good not harm. --Shak. [1913 Webster]
4. To perform, as an action; to execute; to transact to carry out in action; as, to do a good or a bad act; do our duty; to do what I can. [1913 Webster]
Six days shalt thou labor and do all thy work. --Ex. xx. 9. [1913 Webster]
We did not do these things. --Ld. Lytton. [1913 Webster]
You can not do wrong without suffering wrong. --Emerson. Hence: To do homage, honor, favor, justice, etc., to render homage, honor, etc. [1913 Webster]
5. To bring to an end by action; to perform completely; to finish; to accomplish; -- a sense conveyed by the construction, which is that of the past participle done. "Ere summer half be done." "I have done weeping." --Shak. [1913 Webster]
6. To make ready for an object, purpose, or use, as food by cooking; to cook completely or sufficiently; as, the meat is done on one side only. [1913 Webster]
7. To put or bring into a form, state, or condition, especially in the phrases, to do death, to put to death; to slay; to do away (often do away with), to put away; to remove; to do on, to put on; to don; to do off, to take off, as dress; to doff; to do into, to put into the form of; to translate or transform into, as a text. [1913 Webster]
Done to death by slanderous tongues. -- Shak. [1913 Webster]
The ground of the difficulty is done away. -- Paley. [1913 Webster]
Suspicions regarding his loyalty were entirely done away. --Thackeray. [1913 Webster]
To do on our own harness, that we may not; but we must do on the armor of God. -- Latimer. [1913 Webster]
Then Jason rose and did on him a fair Blue woolen tunic. -- W. Morris (Jason). [1913 Webster]
Though the former legal pollution be now done off, yet there is a spiritual contagion in idolatry as much to be shunned. --Milton. [1913 Webster]
It ["Pilgrim's Progress"] has been done into verse: it has been done into modern English. -- Macaulay. [1913 Webster]
8. To cheat; to gull; to overreach. [Colloq.] [1913 Webster]
He was not be done, at his time of life, by frivolous offers of a compromise that might have secured him seventy-five per cent. -- De Quincey. [1913 Webster]
9. To see or inspect; to explore; as, to do all the points of interest. [Colloq.] [1913 Webster]
10. (Stock Exchange) To cash or to advance money for, as a bill or note. [1913 Webster]
11. To perform work upon, about, for, or at, by way of caring for, looking after, preparing, cleaning, keeping in order, or the like.
The sergeants seem to do themselves pretty well. --Harper's Mag. [Webster 1913 Suppl.]
12. To deal with for good and all; to finish up; to undo; to ruin; to do for. [Colloq. or Slang]
Sometimes they lie in wait in these dark streets, and fracture his skull, . . . or break his arm, or cut the sinew of his wrist; and that they call doing him. --Charles Reade. [Webster 1913 Suppl.]
Note: (a) Do and did are much employed as auxiliaries, the verb to which they are joined being an infinitive. As an auxiliary the verb do has no participle. "I do set my bow in the cloud." --Gen. ix. 13. [Now archaic or rare except for emphatic assertion.] [1913 Webster]
Rarely . . . did the wrongs of individuals to the knowledge of the public. -- Macaulay. (b) They are often used in emphatic construction. "You don't say so, Mr. Jobson. -- but I do say so." --Sir W. Scott. "I did love him, but scorn him now." --Latham. (c) In negative and interrogative constructions, do and did are in common use. I do not wish to see them; what do you think? Did C[ae]sar cross the Tiber? He did not. "Do you love me?" --Shak. (d) Do, as an auxiliary, is supposed to have been first used before imperatives. It expresses entreaty or earnest request; as, do help me. In the imperative mood, but not in the indicative, it may be used with the verb to be; as, do be quiet. Do, did, and done often stand as a general substitute or representative verb, and thus save the repetition of the principal verb. "To live and die is all we have to do." --Denham. In the case of do and did as auxiliaries, the sense may be completed by the infinitive (without to) of the verb represented. "When beauty lived and died as flowers do now." --Shak. "I . . . chose my wife as she did her wedding gown." --Goldsmith. [1913 Webster]
My brightest hopes giving dark fears a being. As the light does the shadow. -- Longfellow. In unemphatic affirmative sentences do is, for the most part, archaic or poetical; as, "This just reproach their virtue does excite." --Dryden. [1913 Webster]
To do one's best, To do one's diligence (and the like), to exert one's self; to put forth one's best or most or most diligent efforts. "We will . . . do our best to gain their assent." --Jowett (Thucyd.).
To do one's business, to ruin one. [Colloq.] --Wycherley.
To do one shame, to cause one shame. [Obs.]
To do over. (a) To make over; to perform a second time. (b) To cover; to spread; to smear. "Boats . . . sewed together and done over with a kind of slimy stuff like rosin." --De Foe.
To do to death, to put to death. (See 7.) [Obs.]
To do up. (a) To put up; to raise. [Obs.] --Chaucer. (b) To pack together and envelop; to pack up. (c) To accomplish thoroughly. [Colloq.] (d) To starch and iron. "A rich gown of velvet, and a ruff done up with the famous yellow starch." --Hawthorne.
To do way, to put away; to lay aside. [Obs.] --Chaucer.
To do with, to dispose of; to make use of; to employ; -- usually preceded by what. "Men are many times brought to that extremity, that were it not for God they would not know what to do with themselves." --Tillotson.
To have to do with, to have concern, business or intercourse with; to deal with. When preceded by what, the notion is usually implied that the affair does not concern the person denoted by the subject of have. "Philology has to do with language in its fullest sense." --Earle. "What have I to do with you, ye sons of Zeruiah?" --2 Sam. xvi. 10. [1913 Webster]