Green’s Dictionary of Slang

a mild oath, lit. ‘God’s life!’.

1605		Chapman & Jonson Eastward Ho! I i: ’Slife, man, his father was a malt-man, and his mother sold gingerbread in Christ-church!
1639		Beaumont & Fletcher Wit Without Money II i: ’Slife, how doe I live, why, what dull foole would aske that question.
1641		R. Brome Jovial Crew III i: S’life what shall I say?
1657		Marlowe Lascivious Queen IV ii: Oh! oh! s’life, s’foot, will you fight?
1668		Etherege She Would if She Cou’d I ii: ’Slife, do’st thou think we come here to be Mew’d up.
1675		F. Fane Love in the Dark IV i: ’Slife, I think ’tis my Husband himself!
1679		Behn Feign’d Curtizans 43: But see, the Lady’s here— s’life, dry your eyes, man.
1682		A. Radcliffe ‘Tell me dearest, prythee do’ Poems 30: ’Slife ’tis enough to make one spue.
1695		Congreve Love for Love I i: ’Slife sir, what do you mean, to mew yourself up here with three or four musty books.
1708		W. Taverner Maid the Mistress I i: S’life I’ll not endure it.
1721		Penkethman’s Jests 74: ’Slife, says another marry’d Lady, I’d spit in his Face.
1739		Scots Mag. 1 Dec. 2/2: ‘’Slife! how he banters the old put!’.
1761		G. Colman Jealous Wife IV i: Poor gentleman! ’Slife, if he was but half the man that I am.
1777		Sheridan School For Scandal II i: ’Slife, madam, I say, had you any of these little elegant expenses when you married me?
1787		‘Peter Pindar’ ‘Brother Peter to Brother Tom’ Works (1794) II 61: ’Slife! Thomas, what hath swallow’d all the praise?
1812		‘Hector Bull-us’ Diverting Hist. of John Bull and Brother Jonathan 70: S’life, Bull [...] I’m not to be bamboozled in this way.
1824		Sir W. Scott St Ronan’s Well (1833) 337: ’Slife! wert thou mad?
1838		Crim.-Con. Gaz. 10 Nov. 94/2: ‘Beat you, did he, ’slife, / He beat my daughter, zounds! I’ll beat his wife!’.
1858		‘The Honour of the Family’ Town Talk 10 July 111: Amos! – s’life, only think of that.
1922		Joyce Ulysses 389: ’Slife, I’ll be round with you.