CONTRIBUTIVE | definition in the Cambridge English Dictionary.

Is there a word contributive?

Tending to contribute to a result: conducive, contributory.

What is the verb form of contribution?

verb (used with object), con·trib·ut·ed, con·trib·ut·ing. to give (money, time, knowledge, assistance, etc.) to a common supply, fund, etc., as for charitable purposes. to furnish (an original written work, drawing, etc.) for publication: to contribute stories to a magazine.