zero n: A person regarded as being insignificant; a nonentity.

zilch n:
1. Zero; nothing.
2. A person regarded as being insignificant; a nonentity.
adj.
Amounting to nothing; nil.

zip n: Nothing; nil; zero: received zip for money after doing the job for them.

zit n: A pimple.

zonk
v. zonked, zonking, zonks
v. tr.
1. To stupefy; stun.
2. To intoxicate with drugs or alcohol: I was zonked on drugs
v. intr.
To become intoxicated with drugs or alcohol.