Not the brightest bulb in the chandelier 

Someone slow, dimwitted or stupid - another way of saying "Not the sharpest knife in the drawer". Also, someone who stands out in a crowd as being particularly unintelligent.

Marisa: Why does Eric even bother talking in class - he has no idea what he's talking about.

Michael: What do you expect? I mean he's not the brightest bulb in the chandelier!

Not the brightest bulb in the chandelier by SpencerDuhm March 15, 2009

not the brightest bulb on the porch 

a nice way of refering to a person who is not smart or who does things that are ill-advised

See also: not the sharpest tool in the shed, a few bricks shy of a load, not playing with a full deck

Durwood: My uncle is not the brightest bulb on the porch.

Winthrop: Why do you say that?

Durwood: He saw a sign that said 'keep of the grass'... so flushed his stash o' hash down the drain.

Winthrop: Bloody 'ell!

not the brightest bulb on the porch by Hey-Johnny-Johnny June 11, 2006

not the brightest bulb on the christmas tree 

An analogy describing someone who is not quick-witted and gives the impression of being not very smart.

airhead dimwittedç

You are going to ask John to hook up your PS4? Good luck on that one, you do realize he's not the brightest bulb on the christmas tree.

not the brightest bulb on the christmas tree by TheBigCanucklehead March 15, 2015