Old English brecan "to break, shatter, burst; injure, violate, destroy, curtail; break into, rush into; burst forth, spring out; subdue, tame" (class IV strong verb; past tense bræc, past participle brocen), from Proto-Germanic *brekan (cognates: Old Frisian breka, Dutch breken, Old High German brehhan, German brechen, Gothic brikan), from PIE root *bhreg- "to break" (see fraction). Most modern senses were in Old English. In reference to the heart from early 13c. Meaning "to disclose" is from early 13c.Break bread "share food" (with) is from late 14c. Break the ice is c.1600, in reference to the "coldness" of encounters of strangers. Break wind first attested 1550s. To break (something) out (1890s) probably is an image from dock work, of freeing cargo before unloading it. Ironic theatrical good luck formula break a leg has parallels in German Hals- und Beinbruch "break your neck and leg," and Italian in bocca al lupo. Evidence of a highly superstitious craft (see Macbeth).

c.1300, "act of breaking," from break, v.. Sense of "short interval between spells of work" (originally between lessons at school) is from 1861. Meaning "stroke of luck" is attested by 1911, probably an image from billiards (where the break that starts the game is attested from 1865). Meaning "stroke of mercy" is from 1914. Musical sense, "improvised passage, solo" is attested from 1920s in jazz.