Word Origin & History
late 13c., "living in the world, not belonging to a religious order," also "belonging to the state," from O.Fr. seculer, from L.L. sæcularis "worldly, secular," from L. sæcularis "of an age, occurring once in an age," from sæculum "age, span of time, generation," probably originally
cognate with words for "seed," from PIE base *se(i)- "to sow" (cf. Goth. mana-seþs "mankind, world," lit. "seed of men"). Used in ecclesiastical writing like Gk. aion "of this world" (see cosmos
). It is source of Fr. siècle. Ancient Roman ludi sæculares was a three-day, day-and-night celebration coming once in an "age" (120 years). Secularism "doctrine that morality should be based on the well-being of man in the present life, without regard to religious belief or a hereafter" first recorded 1846.