adj.
  - (of a girl or young woman) attractively lively or cheeky. ▸impudent or cheeky: ![]()  no need to be pert, miss. 
- (of a bodily feature or garment) attractively small and well shaped.
Derivative
  
  Etymology
  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).