One corner short of a pentagon What does it mean?

[mishrashubham]

"One corner short of a pentagon"...What does it mean?

Ok I read this phrase somewhere and I have no idea what it means. Apparently it's a North American thing and is something related to someone's personality or stuff like that.

Can anyone tell me what it is supposed to mean?
Thanks

 

[Jimmy Snyder]

There is something missing in that person's mentality.

 

[jim mcnamara]

The person being described is a square :) You may not be old enough to get that joke...

I haven't heard that one. There are a lot of

He is [fill in the blank] short of [fill in the blank] 
 ex: He is one card short of a full deck

sayings. They all are references to someone's lack of intelligence.

I guess this one is a more geometric approach.

 

[jtbell]

I have to admit I've never seen that phrase before, but a Google search turns up a lot of hits for it. Live and learn!

I do remember seeing another phrase with the same pattern "one ______ short of a ______", but I can't remember what it is! I guess I must be starting to fit that description.

[added] Aha, now I remember it: "one brick short of a full load." Jim's version also rings a bell in the back of my head.

 

[jim mcnamara]

Darn - Jimmy already posted. I expected to really roll with this whole thread...

 

[jtbell]

Let's make up one for physicists:

"One electron short of a full shell."

 

[Astronuc]

Let's make up one for physicists:

"One electron short of a full shell."

A less than noble personality.

 

[Jimmy Snyder]

Sharp as a marble.

 

[mishrashubham]

The person being described is a square :) You may not be old enough to get that joke...

I haven't heard that one. There are a lot of

He is [fill in the blank] short of [fill in the blank] 
 ex: He is one card short of a full deck

sayings. They all are references to someone's lack of intelligence.

I guess this one is a more geometric approach.

Ah I see... I guess it makes sense.

There is something missing in that person's mentality.

Knowing you though, I was at first not sure whether to take this as the real thing or yet another joke.

 

[Astronuc]

There is something missing in that person's mentality.

or someone missing

 

[jtbell]

"One electron short of a full shell."

A less than noble personality.

Yes, probably rather greedy.

 

[Astronuc]

Yes, probably rather greedy.

as halides tend to be with respect to electrons - fluoride being the worst offender.

 

[encorp]

"You're not the sharpest knife in the drawer!"

 

[micromass]

What about "One corner short of a circle"?

 

[KrisOhn]

What about "One corner short of a circle"?

I wish I could have that many corners...

 

[wuliheron]

So smart he's stupid.

 

[edward]

His elevator doesn't go all the way to the top floor.

One taco short of a combination plate.

Dumber than a bag of hammers.

All things my son has said about his boss.

 

[Evo]

A sandwich short of a picnic.

Not the brightest bulb in the lamp.

Doesn't have both oars in the water.

He has a mind like an ink blotter, he soaks it all up, but gets it all backwards.

 

[Ibix]

One banana short of a bunch.

Behind the door when they gave out the brains.

Thick as two short planks.

Given that the original is supposed to be an American saying, is there extra resonance in "a pentagon" versus "the Pentagon"? Quotes about military intelligence being an oxymoron abound.

 

[edward]

A few fries short of a happy meal.

 

[Ben Niehoff]

These are even funnier when you mix them:

"Not the sharpest bulb in the box."

 

[Michael Redei]

These are even funnier when you mix them:

Thick as a Happy Meal.
Not the sharpest knife in the brains.
Doesn't have two short planks in the water.

I think I'm going the wrong way; these are actually making some sense.

 

[collinsmark]

Some of the previous comments were quite humorous.

But seriously though, it must be said that in the American vernacular, the term "square" is not an insult to intelligence. Instead it means dull, conformist, overly conventional or out of touch with current trends.

(This post is square, for example.)

 

[Dembadon]

Here's one I've heard a lot:

"One sandwich short of a picnic."

Here are a few I made up:

"One branch short of a hyperbola."
"One lambda short of a fundamental frequency."
"One surjective mapping short of a finite integral domain."

 

[Michael Redei]

One epsilon away from being negative.

(This is adapted from the shortest mathematical joke: $\mbox{Let }\varepsilon<0$.)

 

[Pythagorean]

One neuron short of a whole brain! Ah hahahahahaha.

...

What?

 

[jim mcnamara]

@Pythagorean - Wait until you are my age. You will fight tooth and nail to keep every neuron... uh what was I saying...?

 

[Pythagorean]

I wonder if sometimes some neurons don't need clearing anyway, though.

 

[jim mcnamara]

I have eight left, don't want any clearing.

 

[SHISHKABOB]

https://www.youtube.com/watch?v=rNBWf54RvsI

This song has oodles of them.

 

[turbo]

He's very intelligent, but not too bright. (said in reference to a newly-minted ChE)

 

[flatmaster]

One diploma short of a BS