unanticipated effect
noun phraseUK /ˌʌnænˈtɪsɪpeɪtɪd ɪˈfekt/
US /ˌʌnænˈtɪsɪpeɪtɪd ɪˈfekt/
A result that happens when you did not expect it.
The new park had an unanticipated effect: more birds came to live nearby.
RELATED WORDS
OTHER MEANINGS
2. A change in a science experiment that the scientist did not plan for.
The medicine helped the headache, but it had an unanticipated effect on sleep.
3. A result of a new rule or plan that nobody predicted.
The school's new lunch rule had an unanticipated effect on how fast students ate.
4. An extra result that shows up later, after the main result.
The app's update had an unanticipated effect on older phones.