Green’s Dictionary of Slang

trinkum-trankum n.

also tringham-trangham, tringum-trangum
[SE trinket]

a whim or fancy.

[UK]B.E. Dict. Canting Crew n.p.: Tringum-trangum, a Whim, or Maggot.
[UK]N. Ward London Spy I 1: My Brains loaded to no purpose, with as many Antiquated Tringum Trangums as are lodg’d in the Whimsical Noddle of an old Astrologer.
[UK]New Canting Dict. [as cit. c.1698].
[UK]Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Tringum trangum, a whim, or maggot.
[UK]Lex. Balatronicum [as cit. 1785].
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.