This sounds really wimpy, but no one is sure where the word "wimp" came from. Some trace it to J. Wellington Wimpy, the pot-bellied, hamburger-munching character from the Popeye comic strip of the late 1920s.
Robert L. Chapman, a professor emeritus at Drew University and editor of the New Dictionary of American Slang, suggests that wimp may date from the early 20th century. Cambridge University students were thought to call women wimps.
While it would seem wimp could be interchanged with other similar terms, there are subtle differences. Here is a list of synonyms and near synonyms, as listed in the New Dictionary of American Slang:
Bozo: a man, especially a muscular type with a meager brain.
Boob: a stupid person; a person who is too innocent and trusting; as in, "There are still boobs, alack, who'd like the old-time gin-mill back" (Sinclair Lewis).
Ding-a-ling: an eccentric person.
Ding-dong: same as ding-a-ling.
Dip: a stupid person, a simpleton; as in, "My grandmother was a woefully crazy lady ... a bit of a dip" (Carol Burnett).
Dork: a despicable person.
Dufus: a stupid, blundering person.
Flake: an eccentric person, especially a colorful individualist.
Geek: a pervert or degenerate, especially one who will do disgusting things to slake deviant appetites.
Goof: a stupid person.
Jerk: a tedious and ineffectual person, especially a man; fool; ninny.
Nebbish: a person without charm, interesting qualities, talent, etc.; as in, " 'Nebbish' ... is simply the one in the crowd that you always forget to introduce" (Budd Schulberg).
Nerd: a tedious, contemptible person.
Weirdo: a very strange, eccentric, repellent person.
Wimp: an ineffectual person; a soft, silly person; a weakling.
Wuss: a weak person.