Definition of tan:
(n) :
a yellowish-brown
colour; a darkening of the
skin resulting from exposure to the sun
"she still has a tan from her vacation in Mexico."
(adj) :
(colour) of a yellowish-brown; having dark skin as a result of exposure to the sun
"mine is the white car parked next to the tan pickup truck."
"no matter how long I stay out in the sun, I never tan — though I do burn."