The noun whistle has long been jocular for the mouth or the...

The noun whistle has long been jocular for the mouth or the throat as used in speaking or singing. The phrase to wet one’s whistle, meaning to take a drink, is found as early as the late 14^th century in The Reeve’s Tale, by the English poet Geoffrey Chaucer (circa 1340-1400):
(interlinear translation – © President and Fellows of Harvard College)
He yexeth, and he speketh thurgh the nose
He belches, and he speaks through the nose
As he were on the quakke, or on the pose.
As if he had hoarseness, or had a cold.
To bedde he goth, and with hym goth his wyf.
To bed he goes, and with him goes his wife.
As any jay she light was and jolyf,
She was as cheerful and jolly as any jay,
So was hir joly whistle wel ywet.
So was her jolly whistle well wetted.
In his textbook Lesclarcissement de la langue francoyse (1530), the teacher and scholar of languages John Palsgrave (died 1554) translated the expression into French:
(1852 edition)
I wete my whystell, as good drinkers do. Je crocque la pie [= I bite the magpie – see explanatory note].
In the sense of the mouth or the throat, whistle has chiefly been used in to wet one’s whistle, but it has sometimes occurred in other contexts. For example, in The Coxcombe (circa 1608-10), by the English playwrights Francis Beaumont (1584-1616) and John Fletcher (1579-1625), Dorothie, “the Tinkers Trull”, says to Viola, who is begging the tinker not to hurt her:
(Folio 2, 1679)
Let’s have no pitty [= no crying out for pity], for if you do, here’s that shall cut your whistle.