1 n impetus, incentive, incitement, irritation, motivation, pressure, spur, stimulation, stimulus, urge
2 vb annoy, arouse, be on one's back (slang) drive, egg on, exhort, harass, hassle (informal) hound, impel, incite, instigate, irritate, lash, nark (Brit., Austral., & N.Z. slang) prick, prod, prompt, propel, spur, stimulate, sting, urge, worry