Irregular means its endings for various tenses and persons and numbers do not follow the typical patterns:
(I am, you are, she is; I was, you were, she was)
Non-action verbs are called "intransitive."
Edit. Sorry, that's an oversimplification. (Actually, it's just wrong.) Intransitive verbs don't have objects. "I'll go in a minute," is intransitive, but it isn't non-action.