"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.
"in difficulties," especially "short of money," 1821, slang; it was earlier a nautical expression, in reference to steering.
also egg-shell, "the shell or outside covering of an egg, especially the hard, brittle, calcareous covering of birds' eggs," early 15c., from egg (n.) + shell (n.). It displaced ay-schelle (Middle English ei-shel, also a measure of quantity, Old English ægscill), from the native word for "egg." As a color term, from 1894. Emblematic of "thin and delicate" from 1835; the figure of tread on eggshells "move cautiously" is attested by 1734.
"egg-shaped," 1760, from Latin ovatus "egg-shaped," from ovum "egg" (see ovary).
also egg-head, 1907, "bald person," from egg (n.) + head (n.). Sense of "intellectual" is attested from 1918, among Chicago newspapermen; popularized by U.S. syndicated columnist Stewart Alsop in 1952 in reference to Adlai Stevenson's presidential campaign.
Adlai Stevenson once told what it was like to be the rare intellectual in politics. "Via ovicapitum dura est," he said, the way of the egghead is hard. [New York Times, Oct. 28, 1982]
word-forming element meaning "egg, eggs," from Greek ōon "egg," cognate with Latin ovum, Old Norse egg,from PIE *ōwyo‑, *ōyyo‑ "egg," which perhaps is a derivative of the root *awi- "bird."
