'To shake the sails' definitions:

Definition of 'To shake the sails'

From: GCIDE

Shake \Shake\, v. t. [imp. Shook; p. p. Shaken, (Shook, obs.); p. pr. & vb. n. Shaking.] [OE. shaken, schaken, AS. scacan, sceacan; akin to Icel. & Sw. skaka, OS. skakan, to depart, to flee. [root]161. Cf. Shock, v.]
1. To cause to move with quick or violent vibrations; to move rapidly one way and the other; to make to tremble or shiver; to agitate. [1913 Webster]
As a fig tree casteth her untimely figs, when she is shaken of a mighty wind. --Rev. vi. 13. [1913 Webster]
Ascend my chariot; guide the rapid wheels That shake heaven's basis. --Milton. [1913 Webster]
2. Fig.: To move from firmness; to weaken the stability of; to cause to waver; to impair the resolution of. [1913 Webster]
When his doctrines grew too strong to be shook by his enemies, they persecuted his reputation. --Atterbury. [1913 Webster]
Thy equal fear that my firm faith and love Can by his fraud be shaken or seduced. --Milton. [1913 Webster]
3. (Mus.) To give a tremulous tone to; to trill; as, to shake a note in music. [1913 Webster]
4. To move or remove by agitating; to throw off by a jolting or vibrating motion; to rid one's self of; -- generally with an adverb, as off, out, etc.; as, to shake fruit down from a tree. [1913 Webster]
Shake off the golden slumber of repose. --Shak. [1913 Webster]
'Tis our fast intent To shake all cares and business from our age. --Shak. [1913 Webster]
I could scarcely shake him out of my company. --Bunyan. [1913 Webster]
To shake a cask (Naut.), to knock a cask to pieces and pack the staves.
To shake hands, to perform the customary act of civility by clasping and moving hands, as an expression of greeting, farewell, good will, agreement, etc.
To shake out a reef (Naut.), to untile the reef points and spread more canvas.
To shake the bells. See under Bell.
To shake the sails (Naut.), to luff up in the wind, causing the sails to shiver. --Ham. Nav. Encyc. [1913 Webster]