The fear of long words is called hippopotomonstrosesquipedaliophobia (or sesquipedaliophobia).It is an intense, irrational fear or anxiety triggered by encountering long, multisyllabic, or obscure words. While it is not formally recognized as a distinct clinical diagnosis in the DSM-5, mental health professionals generally view and evaluate it under the umbrella of a specific phobia or social anxiety.Name Breakdown and IronyThe term itself is famously ironic because it is one of the longest words in the English language. It combines playful and exaggerated elements: