v. 25B6; verb
remember what happened last time he was here : OCCUR, take place, come about; ensue, result, transpire, materialize, arise, crop up, come up, present itself, supervene; N. Amer. informal go down; formal eventuate; poetic/literary come to pass, betide; archaic hap.
I wonder what happened to Susie? : BECOME OF; poetic/literary befall, betide.
they happened to be in London : CHANCE, have the good/bad luck.
he happened on a linnet's nest : DISCOVER, find, find by chance, come across, chance on, stumble on, hit on.