One track mind -
to think entirely or almost entirely about one subject

Bob has a one-track mind. He can only talk about football.

Cut two ways-
to affect both sides of an issue equally.

If our side cannot take along supporters to the game, then yours cannot either. The rule has to cut both ways.
See also: both, cut, ways

Phony as a three-dollar bill-
Something that is bogus.

The whole deal stinks. It's as queer as a three-dollar bill.

On all fours-
on one's hands and knees.

I dropped a contact lens and spent an hour on all fours looking for it.

Take five-
to take a five-minute rest period; to take a short break.

Okay, everybody. Take five! Hey, Bob. I'm tired. Can we take five?

Deep-six something or someone
to get rid of someone or something; to dispose of someone or something. (Refers originally to burying someone or something six feet deep, the standard depth of a grave.)

Take this horrible food out and deep-six it.

A seven day wonder-
to get rid of someone or something; to dispose of someone or something. (Refers originally to burying someone or something six feet deep, the standard depth of a grave.)

Take this horrible food out and deep-six it.

Behind the eigth ball -
A difficult position from which it is unlikely one can escape.
John is behind the eight ball because he started writing his term paper far too late.

Dress to the nines-
To Dress very stylishly with nothing overlooked.

She showed up for the picnic dressed to the nines.

Petfect Ten-
A perfect ten is used to describe something that couldn't get any better - it is already perfect.

Have you heard the new Britney record? I love it. I think it's a perfect ten!