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.

Synonyms for ABNORMAL: unusual, extraordinary, exceptional, unique, rare, uncommon, odd, outstanding; Antonyms of ABNORMAL: normal, common, ordinary, typical, usual, customary, …

uk / æbˈnɔːm ə l / us different from what is normal or usual, in a way that is strange or dangerous: abnormal behaviour / weather

Abnormal psychology is the branch of psychology that studies unusual patterns of behavior, emotion, and thought, which could possibly be understood as a mental disorder. Although …

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. …

adjective not normal, average, typical, or usual; deviating from a standard: abnormal powers of concentration; an abnormal amount of snow; abnormal behavior. Synonyms: odd, unnatural, …