late 14c., losnen (transitive) "make loose, free from tightness," later lousen (early 15c.), from loose (v.) + -en (1). Intransitive sense of "become loose" is from 1670s. Meaning "limber the muscles before physical effort" is from 1955. Related: Loosened; loosening; loosener.

"pertaining to lysis," 1889, from Greek lytikos "able to loose, loosing," from lytos "loosed," verbal adjective of lyein "to unfasten, loose, loosen, untie" (from PIE root *leu- "to loosen, divide, cut apart"). Related: Lytically.

"chemical decomposition by water," 1879, formed in English from hydro- + Greek lysis "a loosening, a dissolution," from lyein "to loosen, dissolve" (from PIE root *leu- "to loosen, divide, cut apart"). Related: Hydrolitic (1875).

late 14c., "to disperse, dissipate, loosen," from Latin solvere "to loosen, dissolve; untie, release, detach; depart; unlock; scatter; dismiss; accomplish, fulfill; explain; remove," from PIE *se-lu-, from reflexive pronoun *s(w)e- (see idiom) + root *leu- "to loosen, divide, cut apart." The meaning "explain, answer" is attested from 1530s; for sense evolution, see solution. Mathematical use is attested from 1737. Related: Solved; solving.

"substance decomposed by electrolysis," 1834, from electro- + Greek lytos "loosed," from lyein "to unfasten, loose, loosen, untie" (from PIE root *leu- "to loosen, divide, cut apart").

"remission, forgiveness," c. 1200, from Old French absolucion, earlier assolucion, from Latin absolutionem (nominative absolutio) "completion, acquittal," noun of action from past-participle stem of absolvere "set free, loosen, acquit," from ab "off, away from" (see ab-) + solvere "to loosen, dissolve; untie, release; dismiss," from PIE *se-lu-, from reflexive pronoun *s(w)e- (see idiom) + root *leu- "to loosen, divide, cut apart." Originally of sins; in general use from c. 1400.

Old English untigan "loosen, unchain," from un- (2) "opposite of" + tie (v.). Related: Untied; untying.

"dissolved," 1890, from Latin solutus, past participle of solvere "to loosen, dissolve," from PIE *se-lu-, from reflexive pronoun *s(w)e- (see idiom) + root *leu- "to loosen, divide, cut apart." In botany, "free, not adhering" (1760).

"dissolution of cells, bacteria, etc.," 1902, from -lysis or from Latin lysis, from Greek lysis "a loosening," from lyein "to unfasten, loose, loosen, untie" (from PIE root *leu- "to loosen, divide, cut apart"). Earlier in the sense "gradual recession of a disease" (1834).

"having the power of decomposing a compound chemical body," 1836, from Latinized form of Greek katalytikos "able to dissolve," from katalyein "to dissolve," from kata "down" (or "completely"), see cata-, + lyein "to loosen" (from PIE root *leu- "to loosen, divide, cut apart").