[af-ter-i-fekt, ahf-]


a delayed effect; an effect that follows at some interval after the stimulus that produces it.
Medicine/Medical. a result appearing after the first effect due to an agent, usually a drug, has gone.

Origin of aftereffect

First recorded in 1810–20; after + effect Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for after-effect

Contemporary Examples of after-effect

Historical Examples of after-effect

  • Little she knew him, or guessed the after-effect of her words.


    Dinah Maria Craik, (AKA Dinah Maria Mulock)

  • The after-effect of light is modified by the duration of exposure to light.

  • The after-effect at the maximum is a recovery to the normal equilibrium.

  • It was the after-effect of his long and difficult river experience.

    Carmen Ariza

    Charles Francis Stocking

  • Most of us, perhaps, have felt this after-effect of dreaming on our waking thoughts.


    James Sully

British Dictionary definitions for after-effect



any result occurring some time after its cause
med any delayed response to a stimulus or agentCompare side effect
psychol any illusory sensation caused by a stimulus that has ceased
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012