"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.
Entries linking to hard-nosed
Old English heard "solid and firm, not soft," also, "difficult to endure, carried on with great exertion," also, of persons, "severe, rigorous, harsh, cruel," from Proto-Germanic *hardu- (source also of Old Saxon hard, Old Frisian herd, Dutch hard, Old Norse harðr "hard," Old High German harto "extremely, very," German hart, Gothic hardus "hard"), from PIE *kortu-, suffixed form of root *kar- "hard."
Meaning "difficult to do" is from c. 1200. Of water, in reference to the presence of mineral salts, 1650s; of consonants, 1775. Hard of hearing preserves obsolete Middle English sense of "having difficulty in doing something." In the sense "strong, spiritous, fermented" from 1789 (as in hard cider, etc.), and this use probably is the origin of that in hard drugs (1955). Hard facts is from 1853; hard news in journalism is from 1918. Hard copy (as opposed to computer record) is from 1964; hard disk is from 1978; the computer hard drive is from 1983. Hard times "period of poverty" is from 1705. Hard money (1706) is specie, silver or gold coin, as opposed to paper. Hence 19c. U.S. hard (n.) "one who advocates the use of metallic money as the national currency" (1844). To play hard to get is from 1945. Hard rock as a pop music style recorded from 1967. To do something the hard way is from 1907.
Middle English nose, from Old English nosu "the nose of the human head, the special organ of breathing and smelling," from Proto-Germanic *nuso- (source also of Old Norse nös, Old Frisian nose, Dutch neus, Old High German nasa, German Nase), from PIE root *nas- "nose."
Used of beaks or snouts of animals from mid-13c.; of any prominent or projecting part supposed to resemble a nose from late 14c. (nose cone in the space rocket sense is from 1949). Meaning "sense of smell" is from mid-14c. Meaning "odor, scent" is from 1894. In Middle English, to have one's spirit in one's nose was to "be impetuous or easily angered" (c. 1400).
Kiv, It could bee no other then his owne manne, that had thrust his nose so farre out of ioynte. ["Barnabe Riche His Farewell to Military Profession," 1581]
To pay through the nose "pay excessively" (1670s) seems to suggest bleeding. Many extended meanings are from the horse-racing sense of "length of a horse's nose," as a measure of distance between two finishers (1908). To turn up one's nose "show disdain, express scorn or contempt" is from 1818 (earlier hold up one's nose, 1570s); a similar notion is expressed in look down one's nose (1907). To say something is under (one's) nose "in plain view, directly in front of one" is from mid-15c. To be as plain as the nose on one's face "very easy to be seen or understood" is from 1590s.