The Collaborative International Dictionary
Rumkin
Rumkin \Rum"kin\, n. [Cf. Rummer, and see -kin.] A popular or jocular name for a drinking vessel. [Obs.]
Wiktionary
rumkin
n. (context obsolete humorous English) A drinking vessel.
Usage examples of "rumkin".
Now Clive, as it happens, is a bit of a rumkin, which is to say a guy who does not fit in very well.