No, the word endurable is an adjective, a word that describes a noun, such as endurable pain or an endurablewait.

The noun forms for the adjective endurable are endurability and endurableness. Another noun form is endurance.

No, the word 'endure' is a verb (endure, endures, enduring, endured).

The adjective forms are the present participle, enduring(an enduring principle); the past participle, endured(an endured treatment); and the adjective endurable(an endurable period of time).