goad (n.) Look up goad at Dictionary.com
O.E. gad "spearhead," from P.Gmc. *gaido (cf. Lombardic gaida "spear"), from PIE *ghai- (cf. Skt. hetih "missile, projectile," O.Ir. gae "spear"). Figurative use is since 16c., probably from the Bible. The verb is from 1579.