1. different from what is usual, typical, or expected; not normal

Examples

• The patient showed abnormal heart rhythms during the test.
• It’s abnormal for her to be late without calling.
• The weather has been abnormal this winter, with unusually warm temperatures.
• Blood tests revealed abnormal levels of certain proteins.
• The child’s abnormal behavior concerned his teachers.
• Scientists detected abnormal activity in the volcano before the eruption.