- secret
- late 14c. (n.), c.1400 (adj.), from L. secretus "set apart, withdrawn, hidden," originally pp. of secernere "to set apart," from se- "without, apart," prop. “on one's own” (from PIE *sed-, from base *s(w)e-; see idiom) + cernere "separate" (see crisis). The verb meaning "to keep secret" (described in OED as "obsolete") is attested from 1590s. Secretive is attested from 1853. Secret agent first recorded 1715; secret service is from 1737; secret weapon is from 1936.