What does Boxing Day have to do with boxing?
also antisocial, 1797, from anti- + social (adj.). First-attested use is in sense of "unsociable;" meaning "hostile to social order or norms" is from 1802.
antisocial an·ti·so·cial (ān'tē-sō'shəl, ān'tī-)adj. Behaving in a manner that violates the social or legal norms of society.