A pointed instrument used to urge on a beast; hence, any necessity that urges or stimulates.

To prick; to drive with a goad; hence, to urge forward, or to rouse by anything pungent, severe, irritating, or inflaming; to stimulate.

a pointed instrument used to prod into motion

goad or provoke,as by constant criticism; "He needled her with his sarcastic remarks"

give heart or courage to

a directing rod, an obedience tool