1. A person who lacks confidence, is irresolute and wishy-washy
   "Don't be such a wimp, just ask her out already";
   - chicken [informal], crybaby [informal], candy-ass [N. Amer, informal], yellow-belly

1. Not do or complete something due to lack of courage
   "He wimped out of the skydiving trip at the last minute";
   - wimp out

1. (physics) a hypothetical subatomic particle of large mass that interacts weakly with ordinary matter through gravitation; postulated as a constituent of the dark matter of the universe
   "Scientists search for WIMPs to explain dark matter";
   - weakly interacting massive particle

Derived forms: wimped, WIMPs, wimps, wimping

Type of: doormat, elementary particle, fundamental particle, weakling, weed [UK, informal], wet [UK, informal], wuss, wussy [informal]

Part of: dark matter

Encyclopedia: Wimp, California