celebrate

/ˈse-lə-ˌbrāt/

Middle English celebraten, borrowed from Latin celebrātus, past participle of celebrāre "to throng, frequent, observe (an occasion, festivity), praise" (probably originally back-formation from earlier concelebrāre "to frequent, honor"), derivative of celebr-, celeber "much used, frequented, widely known, famed," probably going back to *kelesri-, of uncertain origin

verb

  1. to perform (a sacrament or solemn ceremony) publicly and with appropriate rites

  2. to honor (an occasion, such as a holiday) especially by solemn ceremonies or by refraining from ordinary business

  3. to mark (something, such as an anniversary) by festivities or other deviation from routine

A priest celebrates Mass.

keep observe celebrate commemorate mean to notice or honor a day, occasion, or deed. keep stresses the idea of not neglecting or violating. observe suggests marking the occasion by ceremonious performance.