Merriam-Webster Online Dictionary
happen (verb)intransitive verb
1.
to occur by chance - often used with it it so happens I'm going your way
2.
to come into being or occur as an event, process, or result - mistakes will happen
3.
to do, encounter, or attain something by or as if by chance - I happen to know the answer
4.
a) to meet or discover something by chance - happened upon a system that worked Richard Corbin
b) to come or go casually make a chance appearance - he might happen by at any time
5.
to come especially by way of injury or harm - I promise nothing will happen to you
Merriam-Webster Online Thesaurus
happen (verb)to take place
SYNONIMS:
be, befall, betide, chance, come, come about, come down, come off, cook, do, go down, go on, hap, occur, pass, transpireRELATED WORDS:
break, develop, rise, shape (up); arise, come up, crop (up), materialize, spring (up); intervene; fall out, follow, result, turn out; go off, proceedto come upon unexpectedly or by chance
SYNONIMS:
chance (upon), encounter, find, hit (upon), light (on upon), meet, pitch (upon), stumble (on onto), tumble (upon)RELATED WORDS:
luck (out, on, onto, into); confront, face; discover, strike, turn upto come upon face-to-face or as if face-to-face
SYNONIMS:
catch, chance (upon), encounter, happen (upon), stumble (upon)RELATED WORDS:
accost, confront; face, greet, salute; collide (with), crash (into); crisscross, cross, pass; hit (upon), light (upon), tumble (to); reencounter, remeetNEAR ANTONYMS:
avoid, dodge, duck, elude, escape, evade, shake, shun