I am quite familiar with the meaning of "react" as "change in response to a stimulus". For example "She reacted angrily when scolded".

However in the Merriam Webster definition of React in the "transitive verb" section it says "To cause to react". Is this use common?

Can I say for example "The thief used his finger to react the infrared sensor"?

(meaning using the finger to cause the sensor to react)


What would be a good way to rewrite the above sentence?

1 Answer 1


According to the Collins English dictionary, this meaning is the least common:

react in American
(riˈækt ; rēaktˈ)

verb intransitive

  1. to act in return or reciprocally
  2. to act in opposition
  3. to act in a reverse way; go back to a former condition, stage, etc.
  4. to respond to a stimulus; be affected by some influence, event, etc.
  5. Chemistry
    to act with another substance in producing a chemical change

verb transitive

  1. to cause to react; specif., to produce a chemical change in

Note that it's about "react" in American English. As for British English, the same dictionary says nothing about the transitive react.

Speaking of your sentence, I'd say The thief used his finger to start the infrared sensor. I wouldn't use "react" because we are not talking about a chemical reaction.

  • it also added that is specific to chemical changes. So what would be a good way to rewrite the sentence with the thief and the sensor? Commented Aug 30, 2018 at 2:28
  • @KansaiRobot Rather than react, you can use something like engage, activate, or trigger. Commented Aug 30, 2018 at 2:37
  • 1
    @KansaiRobot I've edited my answer.
    – Enguroo
    Commented Aug 30, 2018 at 2:43

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .