Cooperativeness is a noun. A noun is a type of word the meaning of which determines reality. Nouns provide the names for all things: people, objects, sensations, feelings, etc.

What is the meaning of cooperativeness?

adj. 1. Done in cooperation with others: a cooperative effort. 2. Marked by willingness to cooperate; compliant: a cooperative patient.

Is cooperative an adjective?

As an adjective, cooperative describes working together agreeably for a common purpose or goal as in cooperative play or cooperative employee. As a noun, a cooperative is a jointly-owned business or enterprise where members pool their resources to purchase, do work, and/or distribute things.