noun
(chiefly derogatory, slang) Someone who lacks confidence or courage, is weak, ineffectual, irresolute and wishy-washy.
verb
(intransitive, slang) To behave submissively.
(transitive, slang) To make (something) weak or wimpy.
adjective
(slang) Weak, wimpy.
noun
Alternative letter-case form of WIMP.