What is having power to react; tending to reaction; of the nature of reaction. -- Re*act"ive*ly, adv. -- Re*act"ive*ness, n called?

reactive — Having power to react; tending to reaction; of the nature of reaction. -- Re*act"ive*ly, adv. -- Re*act"ive*ness, n. (Webster's 1913.)

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