dime a dozen 

cheap, easily replaced, not valuable

Guys like that are a dime a dozen.

dime a dozen by Anonymous October 26, 2003

One Donut Short of a Dozen 

Some one who is one donut short of a dozen is basically missing a key element to their brains. A.K.A., they are stupid.
One egg short of a dozen works too, but that sounds nasty.

P1: Look at Anna- ew, why is she hugging that cardboard cutout?
P2: Oh, she's one donut short of a dozen. She thinks that's her boyfriend.

One Donut Short of a Dozen by leigh_12 November 27, 2011

dime a dozen 

Anything that is plentiful with little value. Possibly this phrase originated in the early 1900's as a sale discount for candies that cost a penny.

Opinions are a dime a dozen.

dime a dozen by Jason Warren October 26, 2003

Half a dozen 

The same as the number six, but used by people who think "six" is way too long.

I entered the "No usage of words thought to be way too long when actually short" club and there were half a dozen guys armed with bats looking at me.

Half a dozen by Ekker October 14, 2014

dime a dozen 

An expression used to describe something or someone as generic or easy to find.

"Jobs at fast food restaurants are a dime a dozen these days."

dime a dozen by Poiuyt October 25, 2003

dime a dozen 

to be had for next to nothing; common enough to be worthless

Bad teachers are a dime a dozen in most high schools in Los Angeles.

dime a dozen by simone October 23, 2003

dime a dozen 

Mr. Rawley, a prestigious educator from Imagine Schools says, "In reference to dime meaning 10 and dozen, 12, this phrase can be described as an event or phenomenon occurring 10 out of 12 times.

It's believed that "dime a dozen" originated in the 1800's when a hen was expected to yield at least 10 viable eggs out of 12 that are laid.

dime a dozen by Mr. Rawley I crave you April 6, 2009