dimwit
Concise Oxford English Dictionary © 2008 Oxford University Press:
dimwit
▶noun informal a stupid or silly person.
– derivatives
dim-witted adjective,
dim-wittedly adverb,
dim-wittedness noun.
dim-witted adjective,
dim-wittedly adverb,
dim-wittedness noun.
'dimwit' also found in these Oxford entries:

