Merriam-Webster Collegiate Dictionary - uncle tom

 I. noun  Etymology: ~, pious and faithful black slave in ~'s Cabin (1851-52) by Harriet Beecher Stowe  Date: 1922  1. a black who is overeager to win the approval of whites (as by obsequious behavior or uncritical acceptance of white values and goals)  2. a member of a low-status group who is overly subservient to or cooperative with authority the worst floor managers and supervisors by far are women…Some of them are regular ~s — Jane Fonda  • ~ism noun  II. intransitive verb  (~med; ~ming)  Date: 1947 to behave like an ~