occur

Etymology

Originally "meet, meet in argument", borrowed from Middle French occurrer, from Latin occurrō (“run to meet, run against, befall, present itself”) from prefix ob- (“against”) + verb currō (“run, hurry, move”).

verb

1. (intransitive) To happen or take place.
   The liftoff will occur in exactly twelve seconds.
   And no use for anyone to tell Charles that this was because the Family was in mourning for Mr Granville Darracott […]: Charles might only have been second footman at Darracott Place for a couple of months when that disaster occurred, but no one could gammon him into thinking that my lord cared a spangle for his heir. 1959, Georgette Heyer, chapter 1, in The Unknown Ajax
2. (intransitive) To present or offer itself.
   I will write if the opportunity occurs.
3. (impersonal) To come or be presented to the mind; to suggest itself.
   One little incident of my school days occurs to me as amusing.
   It occurred to him to tell me of the problem.
   Apparently it never occurs to them that you can't make rapid, drastic changes in the technology and the economy of a society without causing rapid changes in all other aspects of the society as well, […] 1995, Theodore Kaczynski, Industrial Society and Its Future
4. (intransitive, sciences) To be present or found.
   The chemical monofluoroacetate occurs in all parts of Dichapetalum cymosum, and is responsible for its toxic effects.