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1. Show a response or a reaction to something
   - respond
    
2. Act against or in opposition to
   "She reacts negatively to everything I say"
   - oppose
    
3. Undergo a chemical reaction; react with another substance under certain conditions
   "The hydrogen and the oxygen react"

Derived forms: reacted, reacting, reacts

See also: reactant, reaction, reactive

Type of: act, change state, move, turn

Encyclopedia: React