rare (adj.1)

[thin, few, unusual] late 14c., "thin, airy, porous" (opposed to dense); mid-15c., "few in number and widely separated, sparsely distributed, seldom found, very infrequent;" from Old French rer, rere "sparse" (14c.) and directly from Latin rarus "thinly sown, having a loose texture; not thick; having intervals between, full of empty spaces" (antonym of densus). Sometimes reconstructed to be from a PIE root *ere- "to separate; adjoin."

"Having the particles not close together," hence "few in number," hence, "unusual." Sense of "remarkable from uncommonness," especially "uncommonly good" is from late 15c. (Caxton). Related: Rareness. In chemistry, rare earth is from 1818.

Rare implies that only few of the kind exist : as, perfect diamonds are rare. Scarce properly implies a previous or usual condition of greater abundance. Rare means that there are much fewer of a kind to be found than may be found where scarce would apply. [Century Dictionary, 1895]

rare (adj.2)

[undercooked] 1650s, a variant of Middle English rere, from Old English hrere "lightly cooked," probably related to hreran "to stir, move, shake, agitate," from Proto-Germanic *hrorjan (source also of Old Frisian hrera "to stir, move," Old Saxon hrorian, Dutch roeren, German rühren, Old Norse hroera), from PIE root *kere- "to mix, confuse; cook" (source also of Greek kera- "to mix," krasis "mixture").

Originally of eggs, not recorded in reference to meat until 1784, and according to OED, in this sense "formerly often regarded as an Americanism, although it was current in many English dialects ... and used by English writers in the first half of the 19th c."

rare (v.)

"rise up on the hind legs," as a horse, lion, etc., 1833, dialectal variant of rear (v.1). Sense of "eager" (in raring to go) is recorded by 1909. Related: Rared; raring.

updated on April 22, 2021

Definitions of rare from WordNet

rare (adj.)
not widely known; especially valued for its uncommonness;
a rare word
rare books
rare (adj.)
recurring only at long intervals;
a rare appearance
total eclipses are rare events
rare (adj.)
not widely distributed;
rare herbs
rare patches of green in the desert
rare (adj.)
having low density;
rare gasses
Synonyms: rarefied / rarified
rare (adj.)
marked by an uncommon quality; especially superlative or extreme of its kind; "what is so rare as a day in June"-J.R.Lowell;
a rare skill
Synonyms: uncommon
rare (adj.)
(of meat) cooked a short time; still red inside;
rare roast beef
Etymologies are not definitions. From, not affiliated with etymonline.