mid-14c., "large;" early 15c., "coarse, plain, simple," from Old French gros "big, thick, fat, tall, pregnant; coarse, rude, awkward; ominous, important; arrogant" (11c.), from Late Latin grossus "thick, coarse (of food or mind)," of obscure origin, not in classical Latin. Said to be unrelated to Latin crassus, which meant the same thing, or to German gross "large," but said by Klein to be cognate with Old Irish bres, Middle Irish bras "big." Its meaning forked in English to "glaring, flagrant, monstrous" (1580s) on the one hand and "entire, total, whole" (early 15c.) on the other. Meaning "disgusting" is first recorded 1958 in U.S. student slang, from earlier use as an intensifier of unpleasant things (gross stupidity, etc.). Earlier "coarse in behavior or manners" (1530s) and, of things, "inferior, common" (late 15c.). Gross national product first recorded 1947.