Etymology
Advertisement
relaxation (n.)

late 14c., relaxacioun, "a rupture, a hernia" (a sense now obsolete); mid-15c., "remission of a burden or penalty," from Old French relaxacion (14c.) and directly from Latin relaxationem (nominative relaxatio) "an easing, mitigation, relaxation," noun of action from past-participle stem of relaxare "loosen, open, stretch out" (see relax).

Meaning "relief from hard work or ordinary cares; a state or occupation intended to give mental or bodily relief after effort or ordinary occupations and cares" is from 1540s. Sense of "remission or abatement of rigor or intensity" is from 1690s.

Related entries & more 
Advertisement
stillness (n.)
Old English stilnes "quiet, silence, peace, release, relaxation;" see still (adj.) + -ness.
Related entries & more 
thaw (n.)
"the melting of ice or snow," also "spell of weather causing this," c. 1400, from thaw (v.). Figurative sense is from 1590s; specifically "relaxation of political harshness or hostility" from 1950, an image from the "Cold War."
Related entries & more 
clonus (n.)

"violent muscular spasms, rapidly alternating contraction and relaxation of a muscle," 1817, from Modern Latin, from Greek klonos "turmoil, any violent motion; confusion, tumult, press of battle," a word of uncertain origin. Related: Clonicity.

Related entries & more 
downtime (n.)

also down-time, 1952, "time when a machine or vehicle is out of service or otherwise unavailable;" from down (adj.) + time (n.). Of persons, "opportunity for rest and relaxation," by 1982.

Related entries & more 
Advertisement
let-up (n.)
"cessation, restraint, relaxation, intermission," 1837, from verbal phrase let up "cease, stop" (1787). In Old English the phrase meant "to put ashore" (let out meant "put to sea"). Bartlett (1848) says the noun is "an expression borrowed from pugilists."
Related entries & more 
laxative (adj.)
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.
Related entries & more 
relaxant (adj.)

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).

Related entries & more 
diastole (n.)

"normal rhythmic relaxation of the heart" (alternating with the systole), 1570s, from medical Latin diastole, from Greek diastole "drawing asunder, dilation," from diastellein, from dia "through; thoroughly, entirely" (see dia-) + stellein "to set in order, arrange, array, equip, make ready," from PIE *stel-yo-, suffixed form of root *stel- "to put, stand, put in order," with derivatives referring to a standing object or place. Related: Diastolic.

Related entries & more 
remission (n.)

c. 1200, remissioun, "forgiveness or pardon (of sins)," from Old French remission "forgiveness (of sins), relief" (12c.) and directly from Latin remissionem (nominative remissio) "relaxation, diminishing," etymologically "a sending back, sending away," noun of action from past-participle stem of remittere "slacken, let go, abate" (see remit).

From late 14c. as "release from duty or obligation." Of diseases, fevers, "abatement, temporary subsidence," from early 15c. General sense of "diminution of force or effects" is from c. 1600. By 1736 as "abatement of penalty or punishment."

Related entries & more