originally (c.1500) a verb, "to push, thrust," of unknown origin. Meaning "raise or bend into a hump" is 1670s. Perhaps a variant of bunch. The noun is attested from 1620s, originally "a push, thrust." Figurative sense of "hint, tip" (a "push" toward a solution or answer), first recorded 1849, led to that of "premonition, presentiment" (1904).