simple past tense and past participle of happen

(idiomatic) By coincidence, incidentally

Worrying is not necessary, since it is common to make this mistake or for this to occur.

plural of happener

(dated, 1960s-1970s) One who participates in a happening. / A person who makes things happen. / A person to whom things happen.

to find by chance

(obsolete or dialect) maybe, perhaps.

Something that happens. / A spontaneous or improvised event, especially one that involves audience participation.

present participle of happen

(slang, of a place) Busy, lively; vibrant, dynamic; fashionable. / (slang, of a person or product) Trendy, up-to-the-minute.