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 U.S. 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. Meaning "use a mechanical ground-clearing caterpillar tractor" is from 1942 (see bulldozer); figurative use in this sense is by 1948. Related: Bulldozed; bulldozing.