late 14c., "a solving or being solved," from Old French solucion "division, dissolving; explanation; payment" or directly from Latin solutionem (nominative solutio) "a loosening or unfastening," noun of action from past participle stem of solvere "to loosen, untie, dissolve," from PIE *se-lu-, from reflexive pronoun *s(w)e- (see idiom) + root *leu- "to loosen, divide, cut apart." Meaning "liquid containing a dissolved substance" is first recorded 1590s.
mid-15c., "lax, flaccid, soft, tender" (obsolete or dialectal), from Old French lasche "soft, loose, slack, negligent, cowardly," from laschier "loosen," from Late Latin laxicare "become shaky," related to Latin laxare "loosen," from laxus "loose" (from PIE root *sleg- "be slack, be languid"). The main modern sense of the word, with reference to plant life, "luxuriant in growth," is first attested c. 1600, in Shakespeare. Related: Lushly; lushness.
"to loosen and throw about in disorder, cause to have a disordered or neglected appearance," 1590s, said originally of the hair, later of the dress. It is chiefly a back-formation from disheveled (q.v.).
early 15c., "release" (from an oath or obligation), from Latin absolvere "set free," especially judicially, "acquit" (source also of Old French assoldre (11c.), Modern French absoudre), from ab "off, away from" (see ab-) + solvere "to loosen, untie, release, remove," from PIE *se-lu-, from reflexive pronoun *s(w)e- (see idiom) + root *leu- "to loosen, divide, cut apart." In modern use, "set free from consequences or penalties of actions." Related: Absolved; absolving.
late 14c., relaxen, "to make (something) less compact or dense" (transitive), originally especially in medicine, of muscles, etc., from Old French relaschier "set free; soften; reduce" (14c.) and directly from Latin relaxare "relax, loosen, open, stretch out, widen again; make loose," from re- "back" (see re-) + laxare "loosen," from laxus "loose" (from PIE root *sleg- "be slack, be languid"). A doublet of release.
Meaning "decrease tension" is from early 15c. From 1660s as "to make less severe or rigorous." Intransitive sense of "become loose or languid" is by 1762; that of "become less tense" is recorded from 1935. Of persons, "to become less formal," by 1837. Related: Relaxed; relaxing. As a noun, "relaxation, an act of relaxing," from 17c.
1771, "causing or distinguished by relaxation," from Latin relaxantem (nominative relaxans), present participle of relaxare "to loosen, stretch out" (see relax). As a noun, "a medicine or treatment that relaxes or opens," from 1832. An earlier adjective was relaxative "having the quality of relaxing" (1610s).
late 15c., "to take a lease," from Anglo-French lesser (13c.), Old French laissier "to let, let go, let out, leave" "to let, allow, permit; bequeath, leave," from Latin laxare "loosen, open, make wide," from laxus "loose" (from PIE root *sleg- "be slack, be languid"). Medial -x- in Latin tends to become -ss- or -s- in French (compare cuisse from coxa). The Latin verb also is the source of Spanish laxar; Italian lasciare "leave," lassare "loosen."
Compare release (v.). Meaning "to grant the temporary possession of at a fixed rate" is from 1560s. Related: Leased; leasing. The form has been influenced by the noun, and the modern sense of "to take a lease" might be a new 19c. formation. Lessor, lessee in contract language preserve the Anglo-French vowel.
late 14c., "causing relaxation or looseness," from Old French laxatif (13c.), from Medieval Latin laxativus "loosening," from Latin laxat-, past participle stem of laxare "loosen," from laxus "loose, lax" (see lax). The noun meaning "a laxative medicine, a medicine that relieves constipation by relaxing the intestines" is from late 14c.