Dick

A man’s private part along with him being an ass. He comes off as rude, immature, too sarcastic, thinks he’s funny but he’s not, disrespectful, doesn’t know how to treat a girl, and overall a complete douche.

Zack is being such a dick!

Asshole

A person who isn’t nice, isn’t respectful, and doesn’t treat people correctly.

Zack is being such an asshole!