Definition of "Chap" :

noun: (usually in the plural) leather leggings without a seat; joined by a belt; often have flared outer flaps; worn over trousers by cowboys to protect their legs

noun: a crack in a lip caused usually by cold

noun: a boy or man

"That chap is your host."

noun: a long narrow depression in a surface

verb: crack due to dehydration

"My lips chap in this dry weather."