c.1300, "a period of the year," with ref. to weather or work, from O.Fr. seison (Mod.Fr. saison) "a sowing, planting," from L. sationem (nom. satio) "a sowing," from pp. stem of serere "to sow" (see
sow). Sense shifted in V.L. from "act of sowing" to "time of sowing." In O.Fr.