Words related to private
early 13c., "secret, concealed, not made known in public;" c. 1300, of places, "secluded," from Old French privé "friendly, intimate; a private place," from Latin privatus "private, personal" (see private (adj.)). Meaning "participating in (a secret)" (usually with to) is attested from late 14c. Related: Privily. Privy Council is from c. 1300 in a general sense; specifically of the British government, first attested late 14c. (with French word order) as consaile priue. Privy member "organ of sex" is from late 13c.
c. 1300, propre, "adapted to some purpose, fit, apt; commendable, excellent" (sometimes ironic), from Old French propre "own, particular; exact, neat, fitting, appropriate" (11c.) and directly from Latin proprius "one's own, particular to itself," from pro privo "for the individual, in particular," from ablative of privus "one's own, individual" (see private (adj.)) + pro "for" (see pro-). Related: Properly; properness. As an adverb, "very exceedingly," from mid-15c., but since 19c. the use is considered vulgar.
From early 14c. as "belonging or pertaining to oneself; individual; intrinsic;" also as "pertaining to a person or thing in particular, special, specific; distinctive, characteristic;" also "what is by the rules, correct, appropriate, acceptable." From early 15c. as "separate, distinct; itself." Meaning "socially appropriate, decent, respectable" is recorded by 1704.
Proper name "name belonging to or relating to the person or thing in question, name given to an individual of a class for distinction from others of the same class" is from c. 1300, a sense also preserved in astronomical proper motion "change in the apparent places of a celestial object in the sky relative to other stars or planets" (c. 1300). Proper noun is from mid-15c.