While it might seem like a simple answer, the word "bite" can act as both a verb (to bite) and a noun (a bite of food). When used as a noun, it represents the action of biting, making it an abstract concept.
Here are some examples:
* Verb: The dog bit the mailman.
* Noun: Take a bite of this apple.
In the first sentence, "bite" is an action. In the second, "bite" refers to the act of taking a mouthful of food.