Green’s Dictionary of Slang

langolee n.

the penis.

1793		Bacchanalian Mag. 77: Ye wives with bad husbands, ye maids without any, / Make no more delay but come hither to me; / Your ills I’ll remove, let their number be many, / Your ailments dispel, with my Langolee.
1840		‘Langolee’ in Facetious Songster in Spedding & Watt (eds) Bawdy Songbooks (2011) III 245: Langolee! what sweet vowels compose it / [...] / That Irish shillalegh called Langolee.
1890–1904		Farmer & Henley Sl. and Its Analogues.