"reacting" in the verb sense
1. react, respond
show a response or a reaction to something
2. react, oppose
act against or in opposition to
"She reacts negatively to everything I say"
undergo a chemical reaction react with another substance under certain conditions
"The hydrogen and the oxygen react"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License