Nouns

(n)crust, Earth's crustthe outer layer of the Earth
(n)crust, incrustation, encrustationa hard outer layer that covers something
(n)crust, gall, impertinence, impudence, insolence, cheekiness, freshnessthe trait of being rude and impertinent; inclined to take liberties

Verbs

(v)crustform a crust or form into a crust“The bread crusted in the oven”