scraper n.

early 13c., scrapen, "make erasures (with a knife), erase" (a sense now obsolete); by late 14c. as "to remove (an outer layer) with a sharp or rough instrument," probably in part from Old Norse skrapa "to scrape, erase" and in part from cognate Old English scrapian "to scrape," both from Proto-Germanic *skrapojan (source also of Dutch schrapen, German schrappen), from PIE *skerb- (an extension of the root *sker- (1) "to cut").

The meaning "gather by great effort, collect with difficulty or by small savings" is from 1540s. From 1640s as "draw back the foot as a gesture of obeisance." By 1741 in the transitive sense of "rub harshly on (a surface) in passing along it so as to cause an abrasion or noise." Related: Scraped; scraping.

To scrape acquaintance "get on terms of acquaintance with by careful effort" is from c. 1600. To scrape the bottom of the barrel in the figurative sense of "make do with the most inferior or defective examples of what is wanted for want of any others" is by 1942, in reference to U.S. employers facing worker shortages during the war (the figurative bottom of the (cracker) barrel is by 1938).

mid-15c., "a scraping instrument;" late 15c., "act of scraping or scratching," from scrape (v.). By 1886 as "a scraping sound."

From 1620s as a type of awkward bow or gesture of obeisance, in which the foot is drawn, or "scraped," backward. The meaning "embarrassing or awkward predicament," usually due to imprudence or thoughtlessness, is by 1709, as OED suggests, probably "from the notion of being 'scraped' in going through a narrow passage." In old slang it could mean "a shave" (1859).