The meaning of tan is to make (skin) tan especially by exposure to the sun. Having darker skin than usual because you have been in the sun Past simple and past participle of tan 2
Having brown skin from being in the sun [no object] her skin had tanned to a golden brown. Definition of tanned adjective in oxford advanced learner's dictionary
Tanned (tænd) adj (of skin or person) brown or bronzed after exposure to the sun or uv rays Meanings, etymology, pronunciation and more in the oxford english dictionary /tænd/ /tænd/ ipa guide definitions of tanned adjective (of skin) having a tan color from exposure to the sun synonyms He's tanned and rested after his vacation.
If someone is tanned, their skin is darker because of the time they have spent in the sun Physiology to (cause to) become brown by exposure to ultraviolet rays, as of the sun [~ + object] the sun had tanned his skin