late 14c., from Old English gesnot "nasal mucus," from Proto-Germanic *snuttan (source also of Old Frisian snotta, Middle Low German and Middle Dutch snotte, Middle Low German snute), from the same base as snout. Old English had also a verb snite "wipe or pick one's nose." Meaning "despicable person" is from 1809.
"stubborn," 1927, from hard (adj.) + nose (n.). Earlier of bullets or shells with hard tips, and of dogs that had difficulty following a scent. Not in common use before 1950s, when it begins to be applied to tough or relentless characters generally (Damon Runyon characters, U.S. Marines, Princeton professors, etc.). Soft-nosed seems to have been used only of bullets.
1570s, "perceive the smell of;" 1640s; "pry, search in a meddlesome way;" from nose (n.). Related: Nosed; nosing.
"short and turned up," 1725, in snub-nosed, from snub (v.). The connecting notion is of being "cut short."
c. 1600, in reference to human features or qualities, "characteristic of or resembling monkeys or apes," with -ian + Latin simia "ape," from simus "snub-nosed," from Greek simos "snub-nosed" (like the Scythians), also a masculine proper name, a word of unknown origin.
In 18c. and for a time after Latin Simia was taken as the genus name of the primates, hence the biological meaning "pertaining to monkeys" (by 1863). The noun meaning "an ape or monkey" is attested from 1880.
"a nose turned upwards at the tip," 1778, from pug (n.) based on fancied similarity to the nose of either the monkey or the dog. Related: Pug-nosed (1791). Pug-face is attested by 1768.