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side effect

side effect

259 3.3
An unwanted health change caused by a medicine or treatment
  • noun
  • /ˈsaɪd ɪˌfɛkt/
  • Specialized
translation icon : efecto secundario
  • The new drug was effective in treating the symptoms, but many users reported serious side effects.
  • common side effects
  • drug side effects
  • medication side effects

You're not going to see bad side effects till maybe a year out.

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Examples

  • As in many radical procedures, there are serious side effects to this operation.

  • What are the common side effects of metoprolol?

  • And these things have a lot less side effects, can be very effective.

  • And what are those potential side effects that you mentioned?

  • I should think he would also be concerned about the side effects of all this blood loss.

    Fiction book (1997)
  • As with any new vaccine... there were certain side effects associated with it.

  • There are new pills with fewer side effects.

  • A visit to a pharmacy can also provide much information concerning the side effects of drugs.

    Academic text (1990)
  • We don't know what the side effects are.

  • Well, short-term memory loss is a side effect of sleep deprivation, so it should come back to you.

Synonyms

fallout
vsside effect
102 6.7

Bad effects that happen after an event and cause problems

is an unintended harmful result tied to treatments, not general events
aftereffect
vsside effect
12 5.1

A result that appears after an event, often some time later

is usually an immediate or concurrent unintended effect of treatments
by-product
vsside effect
6 3.9

An extra result that happens because of an action and is not planned

is specific to medical treatments and drugs rather than general outcomes
epiphenomenon
vsside effect
  • Specialized
1 9.9

A side effect that happens with a main event but does not cause it

is an unintended medical consequence, not merely a noncausal by-product

How Serious

complication
  • Specialized
92 6.2
side effect
  • Specialized
259 3.3
reaction
  • Specialized
221 3.0

Surface Forms

side effect singular
side effects plural

Morphology

side + effect

The compound 'side effect' is directly compositional: 'side' (= secondary/adjacent) modifies 'effect' (= result), yielding the meaning 'a secondary or additional effect.' This formation is common cross-linguistically and frequent in medical contexts, so a B1 learner who knows 'side' and 'effect' can readily infer the intended meaning.

Etymology

Side effect comes from the image of something happening at the side of the main effect, a smaller effect next to the main one. So, in medicine it means an extra, usually unwanted or 'unexpected', effect of a drug or treatment.