Word Origin & History
lenient
1652, "relaxing, soothing," from M.Fr. lenient, from L. lenientem (nom. leniens), prp. of lenire "to soften, alleviate, mitigate, allay, calm," from lenis "mild, gentle, calm," probably from PIE base *le(i)- "to leave, yield" (cf. Lith. lenas "quiet, tranquil, tame, slow," O.C.S. lena "lazy," L. lassus "faint, weary," O.E. læt "sluggish, slow," lætan "to leave behind"). Sense of "mild, merciful" (of persons) first recorded 1787. In earlier use was lenitive, attested from 1543 of medicines, 1620 of persons.