occasion · n
occasion (PARTICULAR TIME)
B2 a time when something happens
Dictionary examples:
That was a different/another occasion. (19.2)
We met on several occasions to discuss the issue. (29.2)
He's missed meetings on a number of occasions. (31.0)
occasion (SPECIAL TIME)
B1 an important event or ceremony
Dictionary examples:
His promotion was an occasion for celebration, but he accidentally emailed his resignation! (0.0)
His first day at work was an occasion he'd remember – he accidentally photocopied his face! (0.0)
His graduation was an occasion to celebrate, but he forgot his pants! (0.0)
a special occasion (19.9)
At the wedding, he sang a song written just for the occasion. (28.6)
I have a suit but I only wear it on special occasions. (38.1)
Congratulations on the occasion of your 25th wedding anniversary. (82.8)
on occasion
C2 sometimes, but not often
Dictionary examples:
He has, on occasion, told a small lie. (27.6)