Donk is a slang term used to describe a sluggish or stupid person. There are several synonyms for the word such as bozo, dummy, imbecile, moron, and fool. These words are often used in a derogatory way to insult someone's intelligence. Other synonyms for donk include nitwit, blockhead, dimwit, and simpleton. These words are often used to mock someone's lack of common sense or understanding. While these words may be used in a playful manner between friends, it's important to be aware of the context and intention behind their use to avoid causing harm or offense to others.