A more thorough explanation:

Endeavor (noun): A systematic or continuous effort to achieve a particular goal.

Endeavor (verb): To put in physical or intellectual effort towards achieving a particular goal.

Noun: His endeavor to become a doctor required years of hard work and dedication.

Verb: She endeavored to learn a new language by practicing every day.

These examples illustrate how endeavor can be used as both a noun and a verb to describe a persistent effort towards achieving a specific goal. In the first example, the noun form is used to describe the effort required to become a doctor. In the second example, the verb form is used to describe the effort put into learning a new language.