1797, "seed of an apple (or orange)," a shortened form of pipin "seed of a fleshy fruit" (early 14c.), from Old French pepin (13c.), probably from a root *pipp-, expressing smallness (compare Italian pippolo, Spanish pepita "seed, kernel").
"disease of poultry consisting of a secretion of thick mucus which forms a white scale around the tongue," late 14c., pippe, probably from Middle Dutch pippe "mucus," from West Germanic *pipit (source also of East Frisian pip, Middle High German pfipfiz, German Pips), an early borrowing from Vulgar Latin *pippita, an unexplained alteration of Latin pituita "phlegm" (see pituitary).
"one of the spots on a playing card, dice, etc.," c. 1600, peep, of unknown origin. Because of the original form and difference of dates, it is now not considered to be from pip (n.1). Related: Pips.
"excellent person or thing," 1897, a sense extended from coveted varieties of apple that were raised from seed (so called since late 14c.), from Middle English pipin "seed of certain fruits" (see pip (n.1)).
also pip-squeak, contemptuous name for an insignificant person, 1910, from the trivial noise a young or weak creature makes. In World War I it was the soldier's slang name for a small German shell "which makes both a pip and a squeak when it comes over the trenches" [Farrow, "Dictionary of Military Terms," 1918]. Pip and Squeak (and later Wilfred), the beloved English comic strip animals, debuted May 1919 in the children's section of the Daily Mirror. To squeeze (something) until the pips squeak "exact the maximum from" is attested by 1918, from pip (n.1).
The grossest spectacle was provided by Sir Eric Geddes in the Guildhall at Cambridge. An earlier speech in which, in a moment of injudicious candour, he had cast doubts on the possibility of extracting from Germany the whole cost of the war had been the object of serious suspicion, and he had therefore a reputation to regain. "We will get out of her all you can squeeze out of a lemon and a bit more," the penitent shouted, "I will squeeze her until you can hear the pips squeak" ; his policy was to take every bit of property belonging to Germans in neutral and Allied countries, and all her gold and silver and her jewels, and the contents of her picture-galleries and libraries, to sell the proceeds for the Allies' benefit. [John Maynard Keynes, "The Economic Consequences of Peace," 1919]
Figuratively, "the smallest possible quantity," from late 14c. From early 15c. in English as the smallest unit of weight (originally the weight of a plump, dry grain of wheat or barley from the middle of the ear). From late 14c as "roughness of surface; a roughness as of grains." In reference to wood, "quality due to the character or arrangement of its fibers," 1560s; hence, against the grain (1650), a metaphor from carpentry: cutting across the fibers of the wood is more difficult than cutting along them.
Earliest sense of the word in English was "scarlet dye made from insects" (early 13c.), a sense also in the Old French collateral form graine; see kermes for the evolution of this sense, which was frequent in Middle English; also compare engrain. In Middle English grain also could mean "seed of flowers; pip of an apple, grape, etc.; a berry, legume, nut." Grain alcohol attested by 1854.