side effect

or side-ef·fect

noun

1. any effect of a drug, chemical, or other medicine that is in addition to its intended effect, especially an effect that is harmful or unpleasant.
2. any accompanying or consequential and usually detrimental effect:

   the side effects of air pollution.

side effect

noun

1. any unwanted nontherapeutic effect caused by a drug Compare aftereffect
2. any secondary effect, esp an undesirable one

Word History and Origins

Origin of side effect¹

First recorded in 1880–85

Example Sentences

But millions of rules result in perpetual error, and, as a terminal side effect, make leadership and accomplishment illegal.

From The Daily Beast

“It was a weird side effect of the cold medicine,” he told me once.

From The Daily Beast

It helps to maintain good posture while doing this—a nice side effect.

From The Daily Beast

One predicted side effect of inflation is primordial gravitational waves: twisty ripples in the structure of the Universe.

From The Daily Beast

Halpern prescribes the medi-meth for patients who get recurrent urinary-tract infections—a side effect from Adderall or Ritalin.

From The Daily Beast

Any complex system is sport for a hacker; a side effect of this is the hacker's natural affinity for problems involving security.

From Project Gutenberg

Related Words

• aftereffect
• reaction