'Whippersnapper' definitions:

Definition of 'whippersnapper'

From: WordNet
noun
Someone who is unimportant but cheeky and presumptuous [syn: whippersnapper, jackanapes, lightweight]

Definition of 'Whippersnapper'

From: GCIDE
  • Whippersnapper \Whip"per*snap`per\, n. A diminutive, insignificant, or presumptuous person. [Colloq.] "Little whippersnappers like you." --T. Hughes. [1913 Webster]

Synonyms of 'whippersnapper'

From: Moby Thesaurus