to be removed from the surface of sth or from clothes by washing; to remove sth from the surface of sth or from clothes by washing
to be removed from the surface of sth or from clothes by washing
Those grease stains won't wash off.
wash sth off (sth)
to remove sth from the surface of sth or from clothes by washing
Wash that mud off your boots before you come in.
Definitions from the Oxford Advanced Learner's Dictionary, 9th edition