late 12c., mēl, "an occasion of taking food, a feast, a supply of food taken at one time for relief of hunger," also (c. 1200) "an appointed time for eating;" from Old English mæl, Anglian mēl, "fixed time, occasion; a meal," from Proto-Germanic *mela- (source also of 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- (2) "to measure."
Original sense of "time" is preserved in English in piecemeal; compare Middle English poundmele "by pounds at a time; generously." Meals-on-wheels for a social service offering home delivery of food to persons unable to purchase or prepare their own is attested by 1952 (from 1947 as a mobile food delivery service without reference to social services). Meal ticket first attested 1865 in literal sense of "ticket of admission to a dining hall;" figurative sense of "source of income or livelihood" is from 1899.
"the edible part of ground grain;" Middle English mēle, from Old English melu, from Proto-Germanic *melwan "grind" (source also of Old Frisian mele "meal," Old Saxon melo, Middle Dutch mele, Dutch meel, Old High German melo, German Mehl, Old Norse mjöl "meal;" literally "what is ground;" Old Saxon, Old High German, Gothic malan, German mahlen "to grind"), from PIE root *mele- "to crush, grind." The verb form is not found in Old English. Forms with an -a- begin in late Middle English. "Now commonly understood to exclude the product of wheat (this being called FLOUR)" [OED].
"afraid to say what one really thinks," 1570s; first element perhaps from Old English milisc "sweet," from Proto-Germanic *meduz "honey" (see mead (n.1)), which suits the sense, but if the Old English word did not survive long enough to be the source of this, perhaps the first element is from meal (n.2) on notion of the "softness" of ground flour (compare Middle English melishe (adj.) "friable, loose," used of soils). Related: Mealy-mouth.
"by pieces, in pieces, piece by piece, bit by bit," c. 1300, pece-mele, from piece (n.1) + Middle English meal "fixed time, period of time, occasion," from Old English mælum "at a time," dative plural of mæl "appointed time, food served" (see meal (n.1)). The second element once was more common, as in Old English styccemælum "bit by bit." Compare gearmælum "year by year," and inchmeal.