A goad is a pointy stick or other instrument used to prod something along. To goad is to poke something with that pointy stick. Either way, the pointiness is really essential for making things leap into action.
Originally spelled gad, meaning “spearhead,” goad first came into use as a verb in the 1570s. But say you left your pointy goading stick at home. Have no fear! You can goad people with words, too. Literally or figuratively, a goad prods and pokes and provokes people into doing something. A sheep herder might hustle his flock along with a goad, just as your mom's constant nagging and goading might finally get you sit up straight at the dinner table.