dimbulb

[ dim-buhlb, -buhlb ]
/ ˈdɪmˌbʌlb, -ˈbʌlb /

noun Slang.

a stupid person; dimwit.

Origin of dimbulb

An Americanism dating back to 1930–35; dim + bulb

British Dictionary definitions for dim bulb

dim bulb

noun

informal a slow-witted unintelligent person