noun

reaction

Translation

reaction, response

What was his reaction to the news?

I had a bad reaction to the medicine.

The chemical reaction created heat.

((a/the)) reaction ((to sth.)) a response to something What was his reaction to the news?

((a/the)) reaction ((from sb.)) a response from someone We got a positive reaction from the audience.

Synonyms: response, reply, feedback; Antonyms: action, cause

From Latin 're-' (back) + 'actio' (action). Literally, an 'action back' in response to something.

Think of it as a 're-action' – an action that happens again, or in response to, a first action.