Green’s Dictionary of Slang

an unborn child, often used as a toast.

1635		R. Brome Sparagus Garden III iv: Come here’s a health to the Hans in Kelder, and the mother of the boy, if it prove so.
a.1640		R. Brome New Academy II i: The unbegotten Hans that I mean to clap into thy Kelder.
1644		J. Cleveland Character of a London Diurnall A2: The original sinner in this was not Dutch [...] but Hans-en Kelder.
1655		Fuller Church Hist. of Britain Bk V 36: So Gildas was silenced at the approach of the Welsh St. David, (being then but Hanse en Keldar).
1663		Dryden Wild Gallant V ii: It seems you are desirous I should father this hans en kelder here.
1672		Wycherley Love in a Wood (1967) V i: sir simon: Then I am as it were a Grand father to your new Wives, hans en kelder; to which you are but as it were a father; there’s for you again, Sir — ha, ha.
1680		‘Westminster Wedding’ in Lord Poems on Affairs of State (1965) II 353: For left him (who knows what?) / A teeming lady-wife; nay more, / A Hans-in-kelder got before.
1680		M. Stevenson Wits Paraphras’d 13: What Slaps and Syrrups Nurse did vary, / To make the Bantling to miscarry! / [...] / The sturdy Brat, young Hans en Keldar, / ’Gainst all our Drugs his Lungs did shelter.
1690		D’Urfey Collin’s Walk canto 4 177: Thou hast us’d, and prove by Speeches, The Merit of venereal Itches; Defend the Vertues of your Elders, That get on Strumpets Hans en Kelders.
1693		J. Radcliffe q. in Universal Mag. Aug. (1760) 72/1: The daughter of so wealthy a Gentleman [...] can never want a husband; therefore the sooner you bestow her, the better, that the young Hans en-kelder may be born in wedlock, and have the right of inheritance to so large a patrimony.
1705–07		N. Ward Hudibras Redivivus II:3 6: Some pregnant Dames / [...] / Longing, as I suppose for Pig, / Brought thither to their Husband’s Cost, / Least Hans en Kelder should be lost.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1751		Smollett Peregrine Pickle (1964) 48: When his companions drank to the Hans en kelder, or, Jack in the low cellar, he could not help displaying an extraordinary complacence of countenance.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Hans in kelder, jack in the cellar, i.e. the child in the womb; a health frequently drank to breeding women, or their husbands.
1786		New Foundling Hospital of Wit 278: Augustus, of that name the elder, / Took his friend’s wife with Hans in Kelder.
1811		Lex. Balatronicum [as cit. 1785].
1822		R. Nares Gloss. (1888) I 404: hans en kelder. A Dutch phrase, signifying literally Jack in the cellar, but jocularly used for an unborn infant, and so adopted in English.
c.1850		Duncombe New and Improved Flash Dict.
1867		Sportsman 17 Oct. 2/1: Notes on News [...] [A]ll the fancies in which she indulged while carrying about with her a supposititious Hans in Kelder.