|Origin:||tanner, from Medieval Latin tannare, from tanum; TAN2|
tan1 past tense and past participle tanned, present participle tanning
1 [intransitive and transitive]HBH
if you tan, or if the sun tans you, your skin becomes darker because you spend time in the sun:
She has a pale skin which doesn't tan easily.
to make animal skin into leather by treating it with tannin (=a kind of acid)