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mid-14c., "liberty (to do something), leave," from Old French licence "freedom, liberty, power, possibility; permission," (12c.), from Latin licentia "freedom, liberty, license," from licentem (nominative licens). present participle of licere "to be allowed, be lawful," from PIE root *leik- "to offer, bargain" (cf. Lettish likstu "I come to terms"). Meaning "formal (usually written) permission from authority to do something" (marry, hunt, drive, etc.) is first attested early 15c. Meaning "excessive liberty, disregard of propriety" is from mid-15c. No etymological justification for the spelling with -s-; attempts to confine license to verbal use and licence to noun use (cf. advise/advice, devise/device) seem to have failed.
c.1400, "grant formal authorization," from license (n.). Related: Licenced; Licencing.