/ ˈkrʌsti; NAmE / adjective , noun
■ adjective
1.
( of food ) having a hard outer layer :
fresh crusty bread
2.
( informal ) ( especially of older people ) bad-tempered; easily irritated :
a crusty old man
■ noun
(also crustie ) ( pl. -ies ) ( BrE , informal ) a person who usually has no permanent home, has a dirty or untidy appearance, and rejects the way that most people live in Western society