Synonyms for Pinhead:

n.

eye, pincushion, thimble, bobbin, notions, cotton reel, pin, cotton, needle. wanker, jerk, cretin, spastic, cow, dork, dunce, deadhead. pinhead (noun)
boob, dummy, booby, dumbbell.
stupid person (noun)
dunce.

Other synonyms:

thimble, notions, cotton reel, bobbin, pincushion. cotton. eye, needle. pin. Other relevant words:
notions, pin, dork, pincushion, deadhead, eye, jerk, dunce.