side effect

noun

Definition of side effect

  1. :  a secondary and usually adverse effect (as of a drug) <toxic side effects> —called also side reaction

Examples of side effect in a sentence

  1. Nausea and diarrhea are the side effects of the drug.

  2. the harmful side effects of using chemicals to kill insects

  3. The merger created positive side effects for both companies.

1884

First Known Use of side effect

1884


SIDE EFFECT Defined for English Language Learners

side effect

noun

Definition of side effect for English Language Learners

  • : an often harmful and unwanted effect of a drug or chemical that occurs along with the desired effect

  • : a result of an action that is not expected or intended


Medical Dictionary

side effect

noun

Medical Definition of side effect

  1. :  a secondary and usually adverse effect (as of a drug) <toxic side effects> <a side effect of drowsiness caused by antihistamines>—called also side reaction



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