bull-whip n.

"male of a bovine animal," c. 1200, bule, from Old Norse boli "bull, male of the domestic bovine," perhaps also from an Old English *bula, both from Proto-Germanic *bullon- (source also of Middle Dutch bulle, Dutch bul, German Bulle), perhaps from a Germanic verbal stem meaning "to roar," which survives in some German dialects and perhaps in the first element of boulder (q.v.). The other possibility [Watkins] is that the Germanic word is from PIE root *bhel- (2) "to blow, swell."

An uncastrated male, reared for breeding, as opposed to a bullock or steer. Extended after 1610s to males of other large animals (elephant, alligator, whale, etc.). Stock market sense "one who seeks to cause a rise in the price of a stock" is from 1714 (compare bear (n.)). The meaning "policeman" is attested by 1859.

Bull-necked is from 1640s. Figurative phrase take the bull by the horns "boldly face or grapple with some danger or difficulty" is recorded by 1711 (Swift). To be a bull in a china shop, figurative of careless and inappropriately destructive use of force, is attested from 1812 and was the title of a popular humorous song in 1820s England.

"instrument for flagellating," early 14c., from whip (v.) and perhaps in part from Middle Low German wippe "quick movement." In parliamentary use from 1850 (the verb in this sense is recorded from 1742), from the sense in fox-hunting. The parliamentary whip's duty originally was to ensure the attendance of party members on important occasions.

by 1880, "intimidate by violence," from an earlier noun, bulldose "a severe beating or lashing" (1876), said by contemporary sources to be literally "a dose fit for a bull," a slang word referring to the intimidation beating of black voters (by either blacks or whites) in the chaotic 1876 presidential election. See bull (n.1) + dose (n.). The bull element in it seems to be connected to that in bull-whip and might be directly from that word. The meaning "use a mechanical ground-clearing caterpillar tractor" is from 1942 (see bulldozer); figurative use in this sense is by 1948. Related: Bulldozed; bulldozing.