1530s, of armies, "to retreat, draw back," also, of persons, "to withdraw" to some place, especially for the sake of privacy; from French retirer "to withdraw (something)," from re- "back" (see re-) + Old French tirer "to draw" (see tirade). Related: Retired; retiring.

The sense of "leave one's business or occupation" is by 1660s. The meaning "to leave company and go to bed" is from 1660s. Transitive sense is from 1540s, originally "withdraw, lead back" (troops, etc.); meaning "to remove from active service" is from 1680s. Baseball sense of "to put out" (a batter or team) is recorded by 1874.

"retirement, seclusion, solitude," 1824, American English, irregularly from retire, apparently on the model of privacy.

1580s, "departing, retreating," present-participle adjective from retire (v.). Also "fond of retiring, disposed to seclusion," hence "unobtrusive, modest, subdued" (1766).

1580s, "separated from society or public notice, withdrawn into seclusion," past-participle adjective from retire (v.). Meaning "having given up business" is from 1824. Abbreviation ret'd. attested from 1942.

"one who has retired from a business or occupation," 1945, from retire + -ee. The older word was retirer (16c.) "one who retires or withdraws."

1590s, "act of retreating, act of falling back," also "act of withdrawing into seclusion," from French retirement (1570s); see retire + -ment. Meaning "privacy, state of being withdrawn from society" is from c. 1600; that of "withdrawal from occupation or business" is from 1640s.

Solitude is the condition of being absolutely alone, whether or not one has been with others, or desires to escape from them .... Retirement is comparative solitude, produced by retiring, voluntarily or otherwise, from contact which one has had with others. Seclusion is stronger than retirement, implying the shutting out of others from access .... [Century Dictionary]

"room where a lady may retire to be alone or to receive her intimate friends," 1777, from French boudoir (18c.), literally "pouting room," from bouder "to pout, sulk," which, like pout and bouffant, probably ultimately is imitative of puffing.

1640s, from ascetic (adj.) + -ism. Sometimes also ascetism (1830).

Asceticism goes beyond austerity, being more manifestly excessive and more clearly delighting in self-mortification as a good in itself ; it also generally includes somewhat of the disposition to retire from the world. [Century Dictionary]

"room appropriated for the reception of company," 1640s, short for withdrawing room (16c.; see withdraw), into which ladies would retire after dinner. Earlier in the sense of "private room" as draw-chamber (mid-15c.); drawyng chaumber (early 15c.).

1650s, "to go or retire into the country, live a country life," from Latin rusticatus, past participle of rusticarti "to live in the country," from rusticus (see rustic). In English university slang 18c.-19c., transitive, "to suspend (a student) from studies for a time and send away as punishment." Related: Rusticated; rusticating.