Is it ensure, insure, or assure?
1610s, from French productif (16c.) and directly from Medieval Latin productivus "fit for production," from Latin product-, past participle stem of producere (see produce (v.)). Related: Productively; productiveness.
productive pro·duc·tive (prə-dŭk'tĭv, prō-)
Producing or capable of producing mucus or sputum.
Forming new tissue, as of an inflammation.