pert

Concise Oxford English Dictionary © 2008 Oxford University Press:
pert/pɜːt/

▶adjective

• 1 (of a girl or young woman) attractively lively or cheeky.

  ■ impudent or cheeky: no need to be pert, miss.

• 2 (of a bodily feature or garment) attractively small and well shaped.

– derivatives
pertly adverb,
pertness noun.

– origin ME (in the sense ‘manifest’): from OFr. apert, from L. apertus ‘opened’, past part. of aperire, reinforced by OFr. aspert, from L. expertus (see expert).