c. 1600, "attention to particulars," from French détail, from Old French detail "small piece or quantity," literally "a cutting in pieces," from detaillier "cut in pieces" (12c.), from de- "entirely" (see de-) + taillier "to cut in pieces" (see tailor).
French en détail "piece by piece, item by item" (as opposed to en gros), a commercial term used where we would today use retail, expanded the senses of the noun. Meaning "a minute account or narrative" is from 1690s; that of "an individual part, a particular" is from 1786. In fine arts, "a small, subordinate part," by 1823.
Military sense of "selection of an individual or body of troops for a particular service" is from 1708, from the notion of "distribution in detail of the daily orders first given in general," including assignment of specific duties.
mid-12c. "grant, commission" (recorded earlier in Old English, but as a Latin word), from Old French privilege "right, priority, privilege" (12c.) and directly from Latin privilegium "law applying to one person, bill of law in favor of or against an individual;" in the post-Augustine period "an ordinance in favor of an individual" (typically the exemption of one individual from the operation of a law), "privilege, prerogative," from privus "individual" (see private (adj.)) + lex (genitive legis) "law" (see legal (adj.)).
From c. 1200 as "power or prerogative associated with a certain social or religious position." Meaning "advantage granted, special right or favor granted to a person or group, a right, immunity, benefit, or advantage enjoyed by a person or body of persons beyond the common advantages of other individuals" is from mid-14c. in English. From late 14c. as "legal immunity or exemption."
Formerly of such things as an exemption or license granted by the Pope, or special immunity or advantage (as freedom of speech) granted to persons in authority or in office; in modern times, with general equality of all under the law, it is used of the basic rights common to all citizens (habeas corpus, voting, etc.).
Privilege is also more loosely used for any special advantage: as, the privilege of intimacy with people of noble character. Prerogative is a right of precedence, an exclusive privilege, an official right, a right indefeasible on account of one's character or position : as, the Stuart kings were continually asserting the royal prerogative, but parliament resisted any infringement upon its privileges. [Century Dictionary]
Middle English also had pravilege "an evil law or privilege" (late 14c.), from Medieval Latin pravilegium, a play on privilegium by substitution of pravus "wrong, bad."
loosely, "study and application of extremely small things" in many scientific fields, by 1974 (but not widely used before 1990s), from nano- + technology. Often applied to manipulation of individual atoms and molecules, and sometimes given a precise range (up to 100 nanometers), but the sense of nano- here seems best explained as "very small."
1900 in the biological sense, "individual or form which has arisen by or undergone (genetic) mutation," from Latin mutantem (nominative mutans) "changing," present participle of mutare "to change" (from PIE root *mei- (1) "to change, go, move"). In the science fiction sense, it is attested by 1954. As an adjective from 1903.
1845, in reference to the doctrine of French anarchist/socialist Pierre-Joseph Proudhon (1809-1865) that individual and collective well-being is attainable only by mutual dependence, from French mutuellisme. In biology, "a symbiosis in which two organisms living together mutually and permanently help and support one another," from 1876, from mutual + -ism.
"a buffoon; a zany; a jack-pudding" [Johnson], "One whose business it is to make sport for others by jokes and ridiculous posturing" [Century Dictionary], according to OED, in early use properly a mountebank's assistant, 1670s, from merry + masc. proper name Andrew, but there is no certain identification with an individual, and the name here may be generic.
1670s, "tending to recede, going backward," from Latin recess-, past-participle stem of recedere "to go back, fall back" (see recede) + -ive. Linguistics sense in ancient Greek grammar is from 1879; in genetics, of a hereditary trait present but not perceptibly expressed in the individual organism, 1900, from German recessiv (Mendel, 1865). Related: Recessively; recessiveness.
1570s, "action of pouring liquid from one vessel to another," from French transfusion and directly from Latin transfusionem (nominative transfusio) "a decanting, intermingling," noun of action from past-participle stem of transfundere "pour from one container to another," from trans "across, beyond" (see trans-) + fundere "to pour" (from nasalized form of PIE root *gheu- "to pour"). Sense of "transfering of blood from one individual to another" first recorded 1640s.