1728 in legal sense, "extinguishment by absorption," originally of real estate titles, from merge (v.), on analogy of French infinitives used as nouns (see waiver). From 1889 in the business sense "extinguishment of a security for a debt by the creditor's acceptance of a higher security;" not common until c. 1926. General meaning "any act of merging" is by 1881.
mid-14c., autentik, "authoritative, duly authorized" (a sense now obsolete), from Old French autentique "authentic; canonical" (13c., Modern French authentique) and directly from Medieval Latin authenticus, from Greek authentikos "original, genuine, principal," from authentes "one acting on one's own authority," from autos "self" (see auto-) + hentes "doer, being," from PIE root *sene- (2) "to accomplish, achieve." Sense of "real, entitled to acceptance as factual" is first recorded mid-14c.
Traditionally in modern use, authentic implies that the contents of the thing in question correspond to the facts and are not fictitious (hence "trustworthy, reliable"); while genuine implies that the reputed author is the real one and that we have it as it left the author's hand (hence "unadulterated"); but this is not always maintained: "The distinction which the 18th c. apologists attempted to establish between genuine and authentic ... does not agree well with the etymology of the latter word, and is not now recognized" [OED].
"sacrifice of what commonly constitutes the happiness of life for the sake of duty or higher motive," 1650s; see self + sacrifice (n.). Adjective self-sacrificed attested from 1711. Related: self-sacrificing.
Self-sacrifice goes beyond self-denial in necessarily including the idea of surrender, as of comfort, inclination, time, health, while being also presumably in the line of a real duty. [Century Dictionary]
1815, from the true Simon Pure "the genuine person or thing" (1795), from Simon Pure, name of a Quaker who is impersonated by another character (Colonel Feignwell) in part of the comedy "A Bold Stroke for a Wife" (1717) by Susannah Centlivre, English dramatist and actress. The real Simon Pure is dealt with as an impostor in the play and is believed only after he has proved his identity.
