Green’s Dictionary of Slang

suck-up n.

[suck up v. (1)]

1. one who curries favour with others, a toady, a parasite.

[US]T. Wolfe Electric Kool-Aid Acid Test (1969) 170: He wasn’t a queer or a reporter or any of those other creep suck-ups who were coming around that summer.
[UK]A. Bleasdale No More Sitting on the Old School Bench (1979) 61: Come on, Jacqueline, we’ll give you the benefit of the doubt. How about that? (The start of cries of ‘suck-up’ and ‘Creep creep’).
[UK]Indep. Business Rev. 21 July 7: Suck-up Simon takes the cake.
[NZ]A. Duff Jake’s Long Shadow 194: One of Apeman’s lackey suck-ups, a skinny white guy.

2. attrib. use of sense 1.

[US]Mad mag. Sept. 17: Interview prospective annoying suck-up sidekicks.