/æbˈnɔːməl/-/æbˈnɔːrməl/ adjective
not normal, especially when this seems strange or has a bad effect
NOUNS
abnormal behaviour BrE abnormal behavior AmE
A reduction in oxygen reaching the brain can cause changes in mood and abnormal behaviour.
abnormal cells
Doctors can detect abnormal cells that may become cancerous.
abnormal conditions
The damage was caused by abnormal weather conditions.
abnormal signs/symptoms (=unusual things that show that something may be wrong)
Patients should report any abnormal symptoms to their doctor.
something/nothing/anything abnormal
There was nothing abnormal about him – he was just like anyone else. ANTONYMS → normal