medieval wind instrument, c. 1500, from French saquebute, a kind of bass trumpet with a slide like a trombone. The word is "presumably is identical with" [OED] Old North French saqueboute (14c.), "a lance with an iron hook for pulling down mounted men," based on resemblance, perhaps. That word is from Old North French saquier "to pull, draw" + second element perhaps bouter "to thrust" (from Proto-Germanic *buttan, from PIE root *bhau- "to strike").
Originally in English it had many variant spellings, including sagbutt, shakbott, shagbush. In Daniel iii.5, it is used wrongly to translate Aramaic (Semitic) sabbekha, the name of a stringed instrument (translated correctly in Septuagint as sambuke, and in Vulgate as sambuca, names of stringed instruments in those languages, and probably ultimately cognate with the Aramaic word). The error began with Coverdale (1535), who evidently thought it was a wind instrument and rendered it with shawm; the Geneva translators, evidently following Coverdale, chose sackbut because it sounded like the original Aramaic word, and this was followed in KJV and Revised.