modicum, n. — Green’s Dictionary of Slang

modicum n.

[as well as the comestibles, the vagina is something one can eat v. (4); note Williams (1994) ‘This derives, by synecdoche, from the “woman” sense found in Dekker Roaring Girle I i, where a girl visiting a man is termed “a daintier bit or modicum than any lay upon his trencher at dinner.”’]

the vagina.

1660		Practical Part of Love 67: There was no medium nor modicum like that between Helena’s legs if good parts and ... fine words could but rime to Cunny.
1675		C. Cotton Scoffer Scoff’d (1765) 262: Such knees, such thighs, and such a Bum And such a, such a Modicum.
1707		N. Ward London Terraefilius IV 24: [She] continually wears Drawers, that her Modicum may be kept warm with a Flannel Badge of her Old Authority.
a.1712		N. Ward ‘Merry Observations’ Miscellaneous Writings III 105: [A] Dutch-Woman [who would] keep a Stove under her Petticoats, to keep her Modicum from freezing.
1732		‘Jeremy Jingle’ Spiritual Fornication 21: Her Bum He Kiss’d, and eke her Modicum.
1890–1904		Farmer & Henley Sl. and Its Analogues.