crusted
adjective
[ ˈkrʌstɪd ]
• having or forming a hard outer layer.
• "she washed away the crusted blood"
• old-fashioned or venerable.
• "a crusted establishment figure"
crust
verb
• form into a hard outer layer.
• "the blisters eventually crust over"
Origin:
Middle English: from Old French crouste, from Latin crusta ‘rind, shell, crust’.