late 14c., "careful attention to detail" (a sense now obsolete); also "skilled workmanship;" also "desire to know or learn, inquisitiveness" (in Middle English usually in bad senses: "prying; idle or vain interest in worldly affairs; sophistry; fastidiousness"); from Old French curiosete "curiosity, avidity, choosiness" (Modern French curiosité), from Latin curiositatem (nominative curiositas) "desire of knowledge, inquisitiveness," from curiosus "careful, diligent; inquiring eagerly, meddlesome," akin to cura "care" (see cure (n.)).
Neutral or good sense "desire to see or learn what is strange or unknown" is from early 17c. Meaning "an object of interest, something rare or strange" is from 1640s. Curiosity-shop is from 1818.
1851, "piece of bric-a-brac from the Far East," a shortening of curiosity (n.) in the "object of interest" sense (1640s). Extended by 1890s to rare or interesting bric-a-brac from anywhere.
Curioso (1650s) was a 17c.-18c. word for "one who is curious" (about science, art, etc.) also "one who admires or collects curiosities," from Italian curioso "curious person."
1897, "person who is always listening to other people's conversation; person who gazes around him with undue curiosity," from rubber (n.1) + neck (n.). Popularized in reference to sightseers in automobiles. As a verb, "crane the neck in curiosity," by 1896. Related: Rubbernecking (1896); rubbernecker (1934).
"look inquisitively, look closely or with scrutinizing curiosity," c. 1300, prien "to peer in," a word of unknown origin, perhaps related to late Old English bepriwan "to wink." Related: Pried; prying. As a noun, "act of prying, curious or close inspection," from 1750; meaning "inquisitive, intrusive person" is from 1845.
Men not yet very old can remember when the street railway was a curiosity, patronized at first very much as the roller coaster is now, for the novelty of the thing. [editorial in St. Paul Pioneer-Press, Aug. 17, 1884]
1610s, "full of mystery, obscure, not revealed or explained," from Latin mysterium (see mystery (n.1)) + -ous. Related: Mysteriously; mysteriousness. Earlier in same sense was mysterial (early 15c.), from Late Latin mysterialis.
Mysterious is the most common word for that which is unknown and excites curiosity and perhaps awe; the word is sometimes used where mystic would be more precise. Mystic is especially used of that which has been designed to excite and baffle curiosity, involving meanings in signs, rites, etc., but not with sufficient plainness to be understood by any but the initiated. [Century Dictionary]
God moves in a mysterious way,
His wonders to perform;
He plants his footsteps in the sea,
And rides upon the storm
[Cowper, from the "Olney Hymns," 1779]
Related: Mysteriously; mysteriousness.
also freakout "bad psychedelic drug trip," or something comparable to one, 1966, from verbal phrase freak out, attested from 1965 in the drug sense (from 1902 in a sense "change, distort, come out of alignment"); see freak (n.). There is a coincidental appearance of the phrase in "Fanny Hill:"
She had had her freak out, and had pretty plentifully drowned her curiosity in a glut of pleasure .... [Cleland, "Memoirs of a Woman of Pleasure," 1749]
where the sense is "she had concluded her prank."