Used chiefly attributively before another noun to denote something relating to or characteristic of a moron; informal.
Definitionen
Attributively, informal: foolish; showing a lack of intelligence or good sense. That was a moron move on your part.
Used as a vocative exclamation to address someone regarded as foolish.
Definitionen
An expression of contempt or anger directed at someone considered stupid. Moron! You nearly ran me over.