Occur
late 15th century: from Latin occurrere ‘go to meet, present itself’, from ob- ‘against’ + currere ‘to run’.
wiktionary
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”).
etymonline
occur (v.)
1520s, "meet, meet in argument," from French occurrer "happen unexpectedly" or directly from Latin occurrere "run to meet, run against, befall, present itself," from ob "against, toward" (see ob-) + currere "to run" (from PIE root *kers- "to run"). Sense development is from "meet" to "present itself" to "appear" to "happen" ("present itself in the course of events"). Meaning "to come into one's mind" is from 1620s. Related: Occurred; occurring.
