adj.
 (crustier, crustiest)
  - having or consisting of a crust.
 - (of an old person) easily irritated.
 
n.
 (pl. crusties)
 informal a young person of a subculture characterized by a shabby appearance, a nomadic lifestyle, and a rejection of conventional values.
 
  Derivative
  
    - crustily adv.
  - crustiness n.