The Collaborative International Dictionary of English v.0.48:

desegregate \de*seg"re*gate\ v. t.
   to eliminate laws, regulations, or customs which prohibit
   members of a specific racial or national group from using
   (certain locations, organizations, or facilities); to
   introduce members of a racial or religious group into (a
   community, facility, or organization from which they had been
   barred).
   [PJC]

WordNet (r) 3.0 (2006):

desegregate
    v 1: open (a place) to members of all races and ethnic groups;
         "This school is completely desegregated" [syn:
         desegregate, integrate, mix] [ant: segregate]