What does Boxing Day have to do with boxing?
late 13c., from Old French enquerre "ask, inquire about" (Modern French enquérir), from Vulgar Latin *inquaerere, from Latin in- "into" (see in- (2)) + quaerere "ask, seek" (see query (v.)). Respelled 14c. on Latin model, but half-Latinized enquire still persists. Related: Inquired; inquiring; inquiringly.