"to set or place apart, to detach so as to make alone," by 1786, a back-formation from isolated (q.v.).

The translation of this work is well performed, excepting that fault from which few translations are wholly exempt, and which is daily tending to corrupt our language, the adoption of French expressions. We have here evasion for escape, twice or more times repeated; brigands very frequently; we have the unnecessary and foolish word isolate; and, if we mistake not, paralize, which at least has crept in through a similar channel. Translators cannot be too careful on this point, as it is a temptation to which they are constantly exposed. [The British Critic, April 1799]

As a noun, "something isolated," 1890; from earlier adjectival use (1819), which is from Italian isolato or Medieval Latin insulatus.

"standing detached from others of its kind," 1740, a rendering into English of French isolé "isolated" (17c.), from Italian isolato, from Latin insulatus "made into an island," from insula "island" (see isle (n.)). English at first used the French word (isole, also isole'd, c. 1750), then after isolate (v.) became an English word, isolated became its past participle.

[F]or I think it very natural to suppose, that all the People of this isolated Country, (I ask Pardon for a foreign Word) should have one Language ... ["An Irregular Dissertation Occasioned by the Reading of Father Du Halde's Description of China," 1740]

"put under quarantine" in any sense, also figurative, "to isolate, as by authority," 1804, from quarantine (n.). Related: Quarantined; quarantining; quarantinable.

"having the power or tendency of separating," 1580s, from Medieval Latin segregativus, from Latin segregare "set apart, lay aside; isolate; divide" (see segregate (v.)).

late 14c., sequestren, transitive, "remove (something), set aside; quarantine, isolate (someone); excommunicate;" also intransitive, "separate oneself from," from Old French sequestrer (14c.) and directly from Late Latin sequestrare "to place in safekeeping," from Latin sequester "trustee, mediator," noun use of an adjective meaning "intermediate," which probably is related to sequi "to follow" (from PIE root *sekw- (1) "to follow").

The legal meaning "seize by authority, confiscate" is attested from 1510s. The alternative verb sequestrate is early 15c. (Chauliac), from the Latin past participle sequestratus. Related: Sequestered; sequestering.

1540s, "separate (someone or something) from a generally body or class of things," from Latin segregatus, past participle of segregare "set apart, lay aside; isolate; divide," literally "separate from the flock," from *se gregare, from se "apart from" (see se-) + grege, ablative of grex "herd, flock" (from PIE root *ger- "to gather").

Originally often with reference to the religious notion of separating the flock of the godly from the sinners, later scientifically in reference to classifications. In modern social context, "to force or enforce racial separation and exclusion," by 1898. Intransitive sense of "separate, go apart" is by 1863. Related: Segregated; segregating.