Green’s Dictionary of Slang

1. (US) something strange, peculiar, unknown; also attrib.

1613		Beaumont & Fletcher Coxcomb IV vii: What jiggumbob have we here?
a.1619		Beaumont & Fletcher Knight of Malta IV i: More jiggambobs: is not this the fellow that swam like a duck to the shore .
c.1621		Middleton Women Beware Women II ii: In with her chain of pearl, her ruby bracelets, / Lay ready all her tricks and jiggam-bobs.
1638		R. Brome Antipodes III vi: Kills Monster after Monster; takes the Puppets / Prisoners, knocks downe the Cyclops, tumbles all / Our jigambobs and trinckets to the wall.
1678		S. Butler Hudibras Pt III canto 1 line 108: He rifled all his pokes and fobs / Of gimcracks, whims, and jiggumbobs.
1791		J. Walker Pronouncing Dict. 267/2: Jigumbob, A trinket, a knick-knack. A cant word.
1852		Hereford Jrnl 25 Aug. 3/4: A jiggumbob swain, light as flax his brain, kidnapping querks for a song.
1865		W. Middlesex Advertiser 22 Apr. 2/3: A plan founded on some battle of Jiggumbob fought under his immediate command.
1895		Bath Chron. 7 Mar. 2/2: He described the present Administration as a Jiggumbob or kickshaw Parliament, held together with sticking plaster.
1926		Wood & Goddard Dict. Amer. Sl. 26: jagamaree. Something for which there is no other name, or whose name is momentarily forgotten; a thingumbob, thingumajig, what-dye-call-it, jiggumbob, jiggalorum, whoozis.

2. a euph. for the vagina.

1664

C. Cotton Virgil Travestie (1765) Bk IV 69: I could with this same Youngster tall, / Find in my heart to try a Fall. / [...] / This only (not to mince the Matter) / Has made my Jiggambob to water.