Side Effect
WordNet
noun
(1) Any adverse and unwanted secondary effect
"A strategy to contain the fallout from the accounting scandal"
(2) A secondary and usually adverse effect of a drug or therapy
"Severe headaches are one of the side effects of the drug"
WiktionaryText
Noun
- An unintended consequence of any action in addition to the intended consequence of that action.
- An adverse effect, an unintended consequence of a drug or therapy; usually not a beneficial effect.
- A change in state caused by a function call (typically "side-effect").
- Eiffel is somewhat purist about insisting that functions have no side effects.