Words related to break
also break-down, 1832, "a collapse, a falling apart," from the verbal phrase (attested by late 14c. in the sense "take down by breaking" (trans.); 1831 in the intransitive sense "come down by breaking; 1856 as "to fail through incapacity, excess emotion, etc."); see break (v.) + down (adv.). The noun, specifically of machinery, is from 1838; meaning "an analysis in detail" is from 1936 (from the verbal phrase in the sense "analyze, classify," 1934). Also in 19c. American English "a noisy, lively dance sometimes accompanied by singing" (1864). Nervous breakdown is from 1866.
"first meal of the day," mid-15c., from the verbal phrase; see break (v.) + fast (n.). For vowel shift, see met (v.). An Old English word for it was undernmete (see undern), also morgenmete "morning meal."
Spanish almuerzo "lunch," but formerly and still locally "breakfast," is from Latin admorsus, past participle of admordere "to bite into," from ad "to" + mordēre "to bite" (see mordant). German Frühstück is from Middle High German vruostücke, literally "early bit."
In common with almuerzo, words for "breakfast" tend over time to shift in meaning toward "lunch;" compare French déjeuner "breakfast," later "lunch" (cognate of Spanish desayuno "breakfast"), from Vulgar Latin *disieiunare "to breakfast," from Latin dis- "apart, in a different direction from" + ieiunare, jejunare "fast" (see jejune; also compare dine). Greek ariston in Homer and Herodotus was a meal at the break of day but in classical times taken in the afternoon.
The long/short vowel contrast in break/breakfast represents a common pattern where words from Old English have a long vowel in their modern form but a short vowel as the first element of a compound: Christ/Christmas, holy/holiday, moon/Monday, sheep/shepherd, wild/wilderness, etc.