Having power to react; tending to reaction; of the nature of reaction.
I really love idiot, enlightened characters - these characters who fail to engage with the drama of their immediate circumstances; they fail to be reactive and enrolled by drama as it happens around them. Chuck Palahniuk
Older fatherhood isn't all bad: testosterone rates drop about 1% per year as men age, making them less reactive and more patient, and a professionally established middle-aged man is likely to have more time and money to devote to his kids than a twenty-something who's just getting started. Jeffrey Kluger