Green’s Dictionary of Slang

shift n.

an act of sexual intercourse; usu. in phrs. make a shift, put to a shift etc.

[UK]T. Killigrew Parson’s Wedding (1664) I ii: Serve turn! Prythee, what haste, Secret, that I should put myself to bed with one I might make a shift with?
[UK]Penkethman’s Jests 15: A young Gentlewoman who had marry’d a very wild Spark [...] was innocently saying to him one Day: My Dear, I want some shifts sadly – Shifts! Madam, replies he, Damme, how can that be, when we make so many every Day.
[UK]Gentleman’s Bottle-Companion 13: May we never want courage when put to a shift.
[UK] ‘Job Halls & Mike Hunt’ Lummy Chaunter 83: Job was put to the shift, yet never despair’d, / For I always stand to, he often declar’d.
[UK] ‘Toasts & Sentiments’ Nobby Songster 47: May we never be dry when put to the shift.
[Ire]Joyce Ulysses 375: Young Stephen said indeed to his best remembrance they had but the one doxy between them and she of the stews to make shift with in delights amorous for life ran very high in those days.
[Ire]P. O’Farrell Tell me, Sean O’Farrell 22: There were riots at the Abbey when the word ‘shift’ was used in The Playboy of the Western World [...] I’ll bet those who shouted the loudest saw many a shift besides their wives.

SE in slang uses

In phrases

town shift (n.) [his constantly changing his address to keep ahead of the authorities and outraged victims]

a scoundrel, esp. a card-sharp.

[UK]Head Art of Wheedling 160: The Town-shift is sometimes called Wheedle, Bully, Huff, Rook, Pad.