early 14c., leisir, "opportunity to do something" (as in phrase at (one's) leisure), also "time at one's disposal," from Old French leisir (Modern French loisir) "capacity; permission; leisure, spare time; free will; idleness, inactivity," noun use of infinitive leisir "be permitted," from Latin licere "be permitted" (see licence). The -u- appeared 16c., probably on analogy of words like pleasure. Phrase leisured class attested by 1836.