1. a weak, ineffectual, timid person.
2. wimp out,
a. to be or act like a wimp.
b. to show timidity or cowardice; chicken out.
Synonyms: baby, chicken, chicken liver, coward, cream puff, crybaby, daisy, featherweight, fraidy-cat, jellyfish, lily liver, loser, milksop, momma's boy, namby-pamby, pansy, pantywaist, pushover, scaredy cat, schlemiel, sissy, wuss, yellow belly, Warren T