1publicly acknowledge (a significant or happy day or event) with a social gathering or enjoyable activity:they were celebrating their wedding anniversary at a swanky restaurant [no object]:she celebrated with a glass of champagnewildlife campaigners celebrated after their victory
reach (a birthday or anniversary):the programme celebrates its 40th birthday this year
2perform (a religious ceremony), in particular officiate at (the Eucharist):he celebrated holy communion
3honour or praise publicly:a film celebrating the actor’s career