Definition of Rapscallion

Noun: rapscallion  rap'skal-yun [N. Amer], rap'ska-lee-un [Brit]

1. A deceitful and unreliable scoundrel
   - rogue, knave [archaic], rascal, scalawag, scallywag, varlet [archaic]
    
2. One who is playfully mischievous
   - imp, scamp, monkey, rascal, scalawag, scallywag

See also:
raps
rapscallions