mealyoudaoicibaDictYouDict[meal 词源字典]
meal: [OE] Meal ‘repast’ and meal ‘flour’ are two distinct words. The former originally meant ‘measure’: it goes back via prehistoric Germanic *mǣlaz (source of German mal ‘time, occasion’ and mahl ‘meal’, Dutch maal ‘time, meal’, and Swedish mål ‘meal’) to the Indo-European base *me- ‘measure’, which is also the ancestor of English measure.

The semantic progression from ‘measure’ (which died out for meal in the Middle English period, but survives in the compound piecemeal [13], etymologically ‘measured piece by piece’) to ‘repast’ was via ‘measured or fixed time’ (hence the meaning ‘time, occasion’ in many of the related Germanic forms) and ‘time fixed for eating’. Meal ‘flour’ (as in oatmeal) goes back ultimately to Indo-European *mel-, *mol-, *ml- ‘grind’, source of a wide range of other English words from mild and mill to molar and mould.

From it was descended West and North Germanic *melwam, which has differentiated to German mehl, Dutch meel, Swedish mjōl, Danish mel, and English meal. It has been speculated that mellow [15] may have originated in the use of Old English melu ‘meal’ as an adjective, in the sense ‘soft and rich like flour’.
=> measure, piecemeal; mellow, mild, mill, molar, mould[meal etymology, meal origin, 英语词源]
meal (n.1)youdaoicibaDictYouDict
"food; time for eating," c. 1200 (perhaps late Old English), mel "appointed time for eating," also "a meal, feast," from Old English mæl "fixed time, occasion, a meal," from Proto-Germanic *mæla- (cognates: Old Frisian mel "time;" Middle Dutch mael, Dutch maal "time, meal;" Old Norse mal "measure, time, meal;" German Mal "time," Mahl "meal;" Gothic mel "time, hour"), from PIE *me-lo-, from root *me- "to measure" (see meter (n.2)). Original sense of "time" is preserved in piecemeal. Meals-on-wheels attested from 1961. Meal ticket first attested 1870 in literal sense of "ticket of admission to a dining hall;" figurative sense of "source of income or livelihood" is from 1899.
meal (n.2)youdaoicibaDictYouDict
"edible ground grain," Old English melu "meal, flour," from Proto-Germanic *melwan "grind" (cognates: Old Frisian mele "meal," Old Saxon melo, Middle Dutch mele, Dutch meel, Old High German melo, German Mehl, Old Norse mjöl "meal;" Old Saxon, Old High German, Gothic malan "to grind," German mahlen), from PIE root *mel- (1) "soft" (see mallet).