reactive
Re*act`ive, a. Etym: [Cf. F. réactif.] Defn: Having power to react; tending to reaction; of the nature of reaction. -- Re*act"ive*ly, adv. -- Re*act"ive*ness, n.
Re*act`ive, a. Etym: [Cf. F. réactif.] Defn: Having power to react; tending to reaction; of the nature of reaction. -- Re*act"ive*ly, adv. -- Re*act"ive*ness, n.