Green’s Dictionary of Slang

to defecate.

1577		J. Bishop Beautiful blossomes n.p.: [A] foxe, who vseth when he hathe filled his bellie with meate, as full as it wil hold, to scummer out that whiche he hath eaten.
1596		P. Levens The pathway to health n.p.: For ache in any place, an oyntment. Take and chafe a Stere till he scummer: then take that dung and fry it with Shéepes sewet, or else with Sallet oyle, and it will come to a fine oyntment.
1596		‘Misdiaboles’ Ulysses upon Ajax 30: The picture of a fellow in a square cap, scummering at a privy.
1598		Florio Worlde of Wordes n.p.: Chinchimurra... A skammering of a dog.
1640		R. Brathwaite Ar’t Asleepe, Husband? 83: [T]his loose Lecher could not inwardly bee more polluted, than his fayre Sattin Suite [...] was found hatefully scummered.
1656		‘On the Praise of Fat Men’ in Wardroper (1969) 214: This further know: fat folks do scummer / As much as cows do give in summer.
1661		Wit and Drollery 124: VVhen thou from a full meal dost rise, / Scummer and Urine if tho’rt wise: / Then pipe of right Varinas take,.
1672		J. Phillips Maronides (1678) VI 59: And plagu’d ’um with a Wiltshire Drummer / Till they were forc’d to scowr and scummer.
1673		‘Letter from a Missionary Bawd’ in Carpenter Verse in English from Tudor & Stuart Eng. (2003) 425: Lord Blessington presents the male Baboon, / Beating false time and scammering at the tune.
1683		A Whip for the Devil 123: [When the mighty Lucifer heard this [...] he was taken with such a griping in the Guts, that he scummer’d for fifteen months together.