Green’s Dictionary of Slang

gollumpus n.

[? Scot. golamus, ungainly, large, unshapely]

a large, loutish, uncoordinated person.

[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.