gravyyoudaoicibaDictYouDict[gravy 词源字典]
gravy: [14] To begin with, the word gravy signified a sort of spiced stock-based sauce served with white meat; it was not until the 16th century that its modern sense ‘meat juices’ or ‘sauce made from them’ emerged. Its origins are problematical. It is generally agreed that its v represents a misreading of an n in the Old French word, grané, from which it was borrowed (modern v was written u in medieval manuscripts, and was often very hard to distinguish from n); but what the source of grané was is not clear.

The favourite candidate is perhaps grain (source of English grain), as if ‘sauce flavoured with grains of spice’, but graine ‘meat’ has also been suggested.
=> grain[gravy etymology, gravy origin, 英语词源]
gravy (n.)youdaoicibaDictYouDict
late 14c. (early 14c. in Anglo-French), from Old French grave, graue, apparently a misspelling of grané "sauce, stew," with -n- misread for -u- -- the character used for -v- in medial positions in words in medieval manuscripts. The French word probably originally meant "properly grained, seasoned," from Latin granum "grain, seed" (see grain (n.)). Meaning "money easily acquired" first attested 1910; gravy train (1909) originally was railroad slang for a short haul that paid well. Gravy-boat "small, deep dish for holding gravy or sauce" is from 1827.