I. crust ‧ y 1 /ˈkrʌsti/ BrE AmE adjective
1 . bread that is crusty is pleasant to eat because it has a hard ↑ crust :
a crusty baguette
2 . informal someone who is crusty is bad-tempered SYN grumpy :
a crusty old man
3 . having a thin dry hard layer of something on the surface:
The lake was ringed by crusty salt deposits.
II. crusty 2 BrE AmE noun ( plural crusties ) [countable] British English informal
a young person with a dirty and untidy appearance, usually one who has no permanent job or home and takes part in protests about protecting the environment