The meaning of ABNORMAL is deviating from the normal or average; often : unusual in an unwelcome or problematic way. How to use abnormal in a sentence.

ABNORMAL definition: not normal, average, typical, or usual; deviating from a standard. See examples of abnormal used in a sentence.

ABNORMAL definition: 1. different from what is usual or average, especially in a way that is bad: 2. different from…. Learn more.

Someone or something that is abnormal is unusual, especially in a way that is worrying.

Definition of abnormal adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

abnormal (æbˈnɔːməl) adj 1. not normal; deviating from the usual or typical; extraordinary 2. informal odd in behaviour or appearance; strange

WordReference Random House Learner's Dictionary of American English © 2025 ab•nor•mal /æbˈnɔrməl/ adj. not normal or usual: His wild behavior that day was clearly abnormal. …