Skip to definition.
Get the FREE one-click dictionary software for Windows or the iPhone/iPad and Android apps

Adjective: reactive  ree'ak-tiv
  1. Reacting to a stimulus
    "the skin of old persons is less reactive than that of younger persons";
    - responsive
  2. (physics) participating readily in reactions
    "sodium is a reactive metal"; "free radicals are very reactive"

See also: activated, excited, labile, oxidisable [Brit], oxidizable, sensitive, thermolabile, unstable

Antonym: unreactive

Encyclopedia: Reactive