informal

a stupid person.

He's just a bird-brain - he can't get anything right.

• be on the crest of a wave
• be on the [expensive/heavy/large etc.] side
• be on the expensive side
• be on the fiddle
• be on the fritz
• be on the game
• be on the heavy side
• be on the horns of a dilemma
• be on the large side
• be on the level
• be on the line
• be on the loose
• be on the march
• be on the mend
• be on the money
• be on the piss
• be on the ragged edge
• be on the razzle
• be on the receiving end
• be on the right lines
• be on the right side of
• be on the right track
• be on the rocks
• be on the ropes
• be on the run