From Greek 'mōros' (foolish), coined as a clinical psychology term in 1910 that quickly became a popular insult.
A stupid person.
From Greek 'mōron,' neuter of 'mōros' (foolish, dull). Coined as a clinical psychology term by Henry H. Goddard in 1910 to classify adults with a mental age of 8-12. Like 'idiot' and 'imbecile' before it, the clinical term became a popular insult and had to be abandoned by psychologists. Key roots: mōros (Greek: "foolish, dull").