coincident (adj.)

1560s, "exactly corresponding, having the same nature or character;" 1590s, "happening at the same time, concurrent," from French coincident, from coincider,from Medieval Latin coincidere, literally "to fall upon together," from assimilated form of  Latin com "with, together" (see com-) + incidere "to fall upon" (from in- "upon" + combining form of cadere "to fall," from PIE root *kad- "to fall").