- occasion (n.)
- 1382, from O.Fr. occasion, from L. occasionem (nom. occasio) "opportunity, appropriate time," from occasum, pp. of occidere "fall down, go down," from ob "down, away" + cadere "to fall" (see case (1)). The notion is of a "falling together," or juncture, of circumstances. The verb is first attested 1530. Occasional (1631) was originally "happening on some particular occasion;" sense of "happening as occasion presents itself, without regularity" is from 1630.