What is the verb form of accomplice?

There isn't a direct verb form of "accomplice." The word "accomplice" is a noun.

However, you can use the verb "accomplice" meaning "to aid or abet in the commission of a crime," but it's not a common usage.

Here are some ways to phrase similar ideas:

* Assist: "He assisted in the robbery."

* Abet: "She abetted the crime by providing a getaway car."

* Conspire: "They conspired to defraud the company."

* Collaborate: "The two men collaborated to commit the fraud."

* Aid: "He aided the escape of the prisoner."

The specific verb you use will depend on the context and the nature of the action.