pig widgeon, n. — Green’s Dictionary of Slang

pig widgeon n.

[pig is used as an intensifier; presumably f. SE pigwidgen, pig-widgeon, ‘of obscure origin and meaning’ (OED), although it is either a proper name, as used of a constable by sl. collector Robert Greene (1558–92) or that of a ‘fairy knight’ as suggested by the writer Michael Drayton (1563–1631); however, note widgeon n.]

a fool, a simpleton.

1599		Nashe ‘To his Readers’ Lenten Stuffe A4: I pay them againe in prayse of their Towne and the redde herring: and if it were so goodman Pig-wiggen, were not that honest dealing, pay thou al thy debtes so if thou canst for thy life, but thou art a Ninnihammer.
c.1629		R. Brome City Wit III i: O here comes your Pigg-wiggen.
c.1698		B.E. Dict. Canting Crew n.p.: Pig-widgeon a silly Fellow.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1859		Matsell Vocabulum.