What type of adverb is even?

ad·verb
noun: adverb; plural noun: adverbs
a word or phrase that modifies or qualifies an adjective, verb, or other adverb or a word group, expressing a relation of place, time, circumstance, manner, cause, degree, etc. (e.g., gently, quite, then, there ).

types of adverbs: examples.yourdictionary.com/examples-of-adverbs.html

"Even" is an intensifier.