What is the X in X-mas?
Old English bread "bit, crumb, morsel; bread," cognate with Old Norse brauð, Danish brød, Old Frisian brad, Middle Dutch brot, Dutch brood, German Brot. According to one theory [Watkins, etc.] from Proto-Germanic *brautham, which would be from the root of brew (v.) and refer to the leavening.
But OED argues at some length for the basic sense being not "cooked food" but "piece of food," and the Old English word deriving from a Proto-Germanic *braudsmon- "fragments, bits" (cf. Old High German brosma "crumb," Old English breotan "to break in pieces") and being related to the root of break (v.). It cites Slovenian kruh "bread," literally "a piece."
Either way, by c.1200 it had replaced the usual Old English word for "bread," which was hlaf (see loaf (n.)). Slang meaning "money" dates from 1940s, but cf. breadwinner. Bread-and-butter in the figurative sense of "basic needs" is from 1732. Bread and circuses (1914) is from Latin, in reference to food and entertainment provided by governments to keep the populace happy. "Duas tantum res anxius optat, Panem et circenses" [Juvenal, Sat. x.80].
"to dress with bread crumbs," 1727, from bread (n.). Related: Breaded; breading.
among the Jews was generally made of wheat (Ex. 29:2; Judg. 6:19), though also sometimes of other grains (Gen. 14:18; Judg. 7:13). Parched grain was sometimes used for food without any other preparation (Ruth 2:14). Bread was prepared by kneading in wooden bowls or "kneading troughs" (Gen. 18:6; Ex. 12:34; Jer. 7:18). The dough was mixed with leaven and made into thin cakes, round or oval, and then baked. The bread eaten at the Passover was always unleavened (Ex. 12:15-20; Deut. 16:3). In the towns there were public ovens, which were much made use of for baking bread; there were also bakers by trade (Hos. 7:4; Jer. 37:21). Their ovens were not unlike those of modern times. But sometimes the bread was baked by being placed on the ground that had been heated by a fire, and by covering it with the embers (1 Kings 19:6). This was probably the mode in which Sarah prepared bread on the occasion referred to in Gen. 18:6. In Lev. 2 there is an account of the different kinds of bread and cakes used by the Jews. (See BAKE.) The shew-bread (q.v.) consisted of twelve loaves of unleavened bread prepared and presented hot on the golden table every Sabbath. They were square or oblong, and represented the twelve tribes of Israel. The old loaves were removed every Sabbath, and were to be eaten only by the priests in the court of the sanctuary (Ex. 25:30; Lev. 24:8; 1 Sam. 21:1-6; Matt. 12:4). The word bread is used figuratively in such expressions as "bread of sorrows" (Ps. 127:2), "bread of tears" (80:5), i.e., sorrow and tears are like one's daily bread, they form so great a part in life. The bread of "wickedness" (Prov. 4:17) and "of deceit" (20:17) denote in like manner that wickedness and deceit are a part of the daily life.