reaction noun

1 response

ADJ. extreme, sharp, strong, violent | favourable, positive | adverse, hostile, negative | mixed The speech got a mixed reaction. | angry | first, immediate, initial | delayed Her outburst was a delayed reaction to an unpleasant letter she'd received that morning. | chain The change of plan set off a chain reaction of confusion. | mixed | common, general, public | natural, normal | automatic, gut, instinctive, knee-jerk, spontaneous The incident calls for a measured response, avoiding knee-jerk reactions. | nervous | emotional | critical The critical reaction to his first novel has been positive.

VERB + REACTION get, have, meet with The play met with a mixed reaction from the critics. | bring, cause, produce, provoke, set off, spark (off), trigger (off) She was surprised at the reaction brought by the mention of his delayed a delayed reaction to the drugs | allergic

VERB + REACTION have, suffer She had a very bad allergic reaction to the peanuts. | cause, produce

PREP. ~ to A small minority of patients suffer an adverse reaction to the treatment. name. | gauge, judge (by/from) He eyed her cautiously, trying to gauge her reaction. Judging by her reaction, she liked the present.

PREP. in ~ to There's been a drop in ticket sales in reaction to the review. | ~ against Her rebellious attitude is just a reaction against her strict upbringing. | ~ to the public reaction to the news

2 (usually reactions) ability to react quickly

ADJ. fast, good, lightning, quick | slow, sluggish

VERB + REACTION have She has very quick reactions. | speed up | slow down Alcohol has the effect of slowing down your reactions.

REACTION + NOUN time Your reaction time increases when you are tired.

3 chemical reaction

ADJ. chain | chemical, nuclear

VERB + REACTION cause, produce, start, trigger | stop | speed up | slow down

REACTION + VERB occur, take place

PREP. during/in a/the ~ the energy given out during the reaction | ~ between studying the reactions between certain gases | ~ with the fuel's chemical reaction with the surrounding water

4 allergy

ADJ. adverse, bad | mild, slight |