Despite the form lunching in the 1650s source OED discounts that it possibly could be from lunch (v.), which is first attested more than a century later. It suggests perhaps an analogy with truncheon, etc., or to simulate a French origin. Especially in reference to an early afternoon meal eaten by those who have a noontime dinner.
"remains of food left from a meal, a table scrap," mid-15c. (from c. 1300 in Anglo-Latin), originally of animal food, but not common until late 16c.; probably cognate with early Dutch ooraete, Low German ort, from or-, privative prefix, + etan "to eat" (from PIE root *ed- "to eat"). Perhaps from an unrecorded Old English word.
c. 1300, "a supply or provision of food for one meal," from Old French mes "portion of food, course at dinner," from Late Latin missus "course at dinner," literally "a placing, a putting (on a table, etc.)," from past participle of mittere "to put, place," in classical Latin "to send, let go" (see mission). For sense evolution, compare early Middle English sonde "a serving of food or drink; a meal or course of a meal," from Old English sond, sand, literally "a sending," the noun form of send (v.).
Meaning "a communal eating place" (especially a military one) is attested by 1530s, from the earlier sense of "a company of persons eating together at the same table" (early 15c.), originally a group of four. The sense of "mixed food," especially "mixed food for animals" (1738), probably is what led to the contemptuous colloquial use of mess for "a jumble, a mixed mass" (1828) and the figurative sense of "state of confusion, a situation of disorder" (1834), as well as "condition of untidiness" (1851).
General use for "a quantity" of anything is attested by 1830. Meaning "excrement" (of animals) is from 1903. Mess-hall "area where military personnel eat and socialize" is by 1832. Mess-kit "the cooking- and table-utensils of a camp, with the chest in which they are kept" is by 1829. Mess-locker "a small locker on shipboard for holding mess-gear" is by 1829.
"mass of flour or meal moistened and mixed for baking," Middle English dogh, from Old English dag "dough," from Proto-Germanic *daigaz "something kneaded" (source also of Old Norse deig, Swedish deg, Middle Dutch deech, Dutch deeg, Old High German teic, German Teig, Gothic daigs "dough"), from PIE root *dheigh- "to form, build." Meaning "money" is from 1851 (compare bread (n.)).
the last canonical service of the day, early 13c., cumplie, compelin, from Old French complie (12c.), from Medieval Latin completa, from Latin completa (hora), from completus (see complete (adj.)); with unetymological -n-. So called because the service usually completes the religious exercises of the day. Originally it was said after the evening meal and before retiring to bed, but in later medieval times it shifted to immediately after vespers.
"decorated screen behind an altar; brick or stone back of a fireplace," late 14c., rere-dose, from Anglo-French rere-, an archaic combining form of rear (n.), + dos "back" (see dossier). But Klein's sources suggest it is aphetic of Anglo-French areredos, from Old French arere "at the back" (Modern French arrière). For rere-, compare rere-main "a backhand stroke" (c. 1300), rere-supper "a late supper after the ordinary meal."
1707, "dust, powdery substance," from Latin farina "ground wheat, flour, meal," from far (genitive farris) "husked wheat, emmer; grain, flour," from Proto-Italic *fars "flour," from PIE *bhars-, with cognates in Old Irish bairgen "bread, loaf," Welsh bara "bread," Serbo-Croatian brašno "flour, food," Latvian bariba "food," Gothic barizeins "from barley," Old Norse barr "grain," Old English bere "barley;" according to de Vaan perhaps a loan-word from a non-IE language.