"softness, smoothness, mildness," early 15c., from Old French lénité or directly from Latin lenitatem (nominative lenitas) "softness, smoothness, gentleness, mildness," from lenis "soft, mild" (from PIE root *‌‌lē- "to let go, slacken").

"one to whom a lease is given," late 15c., from Anglo-French lesee, Old French lessé, past participle of lesser "to let, to leave" (10c., Modern French laisser), from Latin laxare, from laxus "loose" (see lax).

also bloodletting, in medicine, "act of letting blood by opening a vein," as a measure in treatment of disease, early 13c., blod letunge, from blood (n.) + letting. Hyphenated from 17c., one word from mid-19c. Old English had blodlæte (n.) "blood-letting," from blodlætan "to bleed, let blood."

c. 1600, "descend, sink, grow less or lower" (intransitive), from lower (adj.), comparative of low (adj.). Transitive meaning "let down, cause to descend" attested from 1650s. Related: Lowered; lowering. In the transitive sense "to cause to descend" the older verb was low (Middle English lahghenn, c. 1200), which continued in use into the 18c.

c. 1400, promisse, "a solemn pledge; a vow; a declaration in reference to the future made by one person to another, assuring the latter that the former will do, or not do, a specified act," from Old French promesse "promise, guarantee, assurance" (13c.) and directly from Latin promissum "a promise," noun use of neuter past participle of promittere "send forth; let go; foretell; assure beforehand, promise," from pro "before" (from PIE root *per- (1) "forward," hence "in front of, before") + mittere "to release, let go; send, throw" (see mission).

Sense of "that which affords a basis for hope or expectation of future excellence or distinction" is by 1530s.

"disposition to go to extremes in doctrine or practice," 1848, from extreme + -ism.

I would remind you that extremism in the defense of liberty is no vice! And let me remind you also that moderation in the pursuit of justice is no virtue. [Barry Goldwater (1909-1998), acceptance speech as Republican candidate for President, 1963]

"one who grants a lease," late 14c., from Anglo-French lessor (late 13c.), from verb lesser "to let, to leave" (10c., Modern French laisser), from Latin laxare, from laxus "loose" (from PIE root *sleg- "be slack, be languid").

1530s, "metal band or ring worn around the upper arm," diminutive of arm (n.1) with -let. Compare bracelet. The Latin word was armilla. As "a small intrusion of the sea into the land," also 1530s.

1610s, "allowable," from French admissible, from past-participle stem of Latin admittere "allow to enter, admit, give entrance," from ad "to" (see ad-) + mittere "let go, send" (see mission). The meaning "capable of being allowed entrance" is from 1775; the specific sense of "capable of being used in a legal decision or judicial investigation" is by 1849.

(1755-1793), queen consort of Louis XVI; as the name for a decorative style of France in that period, by 1887. She likely did not say "let them eat cake" (see cake (n.)). The city of Marietta, Ohio, U.S., founded in 1788, was named for her in honor of Louis XVI's financial support of the American Revolution.