undying (adj.)

prefix of negation, Old English un-, from Proto-Germanic *un- (source also of Old Saxon, Old Frisian, Old High German, German un-, Gothic un-, Dutch on-), from PIE *n- (source of Sanskrit a-, an- "not," Greek a-, an-, Old Irish an-, Latin in-), combining form of PIE root *ne- "not." Often euphemistic (such as untruth for "lie").

The most prolific of English prefixes, freely and widely used in Old English, where it forms more than 1,000 compounds. It underwent a mass extinction in early Middle English, but emerged with renewed vigor 16c. to form compounds with native and imported words. It disputes with Latin-derived cognate in- (1) the right to form the negation of certain words (indigestable/undigestable, etc.), and though both might be deployed in cooperation to indicate shades of meaning (unfamous/infamous), typically they are not.

It also makes words from phrases (such as uncalled-for, c. 1600; undreamed-of, 1630s; uncome-at-able, 1690s; unputdownable, 1947, of a book; un-in-one-breath-utterable, Ben Jonson; etc., but the habit is not restricted to un-; such as put-up-able-with, 1812). As a prefix in telegramese to replace not and save the cost of a word, it is attested by 1936.

mid-12c., dien, deighen, of sentient beings, "to cease to live," possibly from Old Danish døja or Old Norse deyja "to die, pass away," both from Proto-Germanic *dawjan (source also of Old Frisian deja "to kill," Old Saxon doian, Old High German touwen, Gothic diwans "mortal"), from PIE root *dheu- (3) "to pass away, die, become senseless" (source also of Old Irish dith "end, death," Old Church Slavonic daviti, Russian davit' "to choke, suffer").

It has been speculated that Old English had *diegan, from the same source, but it is not in any of the surviving texts and the preferred words were steorfan (see starve), sweltan (see swelter), wesan dead ("become dead"), also forðgan and other euphemisms.

Languages usually don't borrow words from abroad for central life experiences, but "die" words are an exception; they often are hidden or changed euphemistically out of superstitious dread. A Dutch euphemism translates as "to give the pipe to Maarten."

Regularly spelled dege through 15c., and still pronounced "dee" by some in Lancashire and Scotland. Of plants, "become devitalized, wither," late 14c.; in a general sense of "come to an end" from mid-13c. Meaning "be consumed with a great longing or yearning" (as in dying to go) is colloquial, from 1709. Used figuratively (of sounds, etc.) from 1580s; to die away "diminish gradually" is from 1670s. To die down "subside" is by 1834. Related: Died; dies.

To die out "become extinct" is from 1865. To die game "preserve a bold, resolute, and defiant spirit to the end" (especially of one facing the gallows) is from 1793. Phrase never say die "don't give up or in" is by 1822; the earliest contexts are in sailors' jargon.

"Never look so cloudy about it messmate," the latter continued in an unmoved tone—"Cheer up man, the rope is not twisted for your neck yet. Jack's alive; who's for a row? Never say die while there's a shot in the locker. Whup;" [Gerald Griffin, "Card Drawing," 1842]