The coast is clear

'The coast is clear' means that whoever you were hiding from is now gone.

Example:
-Has he gone yet?
-Yes! The coast is clear!

Good ol' boy

When you hear someone talking about a 'good ol' boy,' it conjures up the image of a guy who lives in a small, rural town, drives an old beat-up pick-up truck with a Confederate flag in the back window (which he sees as a symbol of Southern pride), probably chews tobacco and may or may not have a high school education. They are perceived to be prejudiced and racist. Calling someone this is not a compliment, unless you also happen to be a 'good ol' boy.'

Example:
-I live in New York now, but back home, I knew a lot of good ol' boys.
-Really?

Potluck

A 'potluck' is a party or gathering where everyone brings a dish (i.e., salad, entree or dessert) to share with everyone else.

Example:
-What are you going to take to the potluck next week?
-My usual -- my grandmother's potato salad.

R.S.V.P.

'R.S.V.P.' is French for 'Réponde, s'il vous plaît,' which means literally, 'Respond, if it pleases you.' You will see this at the bottom of a formal invitation, such as to a black-tie event or a wedding. Because sometimes people are not good about responding, now you will sometimes see 'Regrets only,' which means you only have to reply if you can't come. Each letter is pronounced separately, not as one word.

Example:
-Did you R.S.V.P. for your cousin's wedding?
-Yes, I mailed it yesterday.

Under the gun

If you're 'under the gun,' it means you're under a great deal of pressure to get something finished and there's not much time left.

Example:
-Hi, Elizabeth. So, how is your sister doing?
-I'm sorry, I really can't talk right now. I'm under the gun. My presentation has to be ready in an hour.

T.M.I.

'T.M.I.' (each letter in pronounced separately) means 'Too much information.' It is used as a response after someone has said more than you wanted to know.

Example:
-We had sex on our first date!
-T.M.I.!

It is what it is.

'It is what it is' is an expression someone will say when someone else has complained about a situation, and the person realizes that there's nothing they can do to change it. By saying this, they're trying to get the person who complained to realize it.

Example:
-I wish they weren't such micro-managers. It drives me crazy.
-It is what it is. I doubt they're going to change at this point.

Rub it in

If you 'rub it in,' it means you make a comment to a person who is in trouble or upset which only serves to make them more upset.

Example:
-I can't believe I broke my leg!
-And tomorrow, we're leaving to go skiing for a week.
-Hey! You don't have to rub it in!

Speak of the devil!

When a person has been talking about someone, and then that person suddenly appears, the person can say, "Speak of the devil!" If you walk up to a group of people and someone says this, you know they've been talking about you.

Example:
-What is Patrick going to do after he graduates?
-Well, first he wants to do some traveling with some friends, and then he'll move to Manhattan to.... Speak of the devil! How are you, Patrick?

Pretty please!

'Pretty please' is an expression that mostly kids use when they really want something and are trying to convince their parents. 'Pretty please with a cherry on top' is an extended, and even more pleading version.

Example:
-Mom, can I spend the night at Catherine's house tonight?
-Well...
-Pretty please!

Bat-shit crazy

'Bat-shit crazy' is used to describe someone who you think is just plain crazy and beyond any hope of getting better. In reality, it's not usually used to describe a person who is truly mentally ill, but rather a person who has such outlandish, uninformed and offensive beliefs that you're sure they must be crazy.

Example:
-That presidential candidate is bat-shit crazy!
-I know! If he wins, I'm moving to Canada!

Gold digger

A 'gold digger' is a person who wants to marry a wealthy person. Sometimes it's with the intent of living a better lifestyle, and sometimes it's planned in advance to later get divorced and try to get as much money out of the person as possible. This is why many extremely wealthy people sign a pre-nup (prenuptial agreement) before they get married, which states who gets what in the case of a divorce.

Example:
-I can't believe that 22 year old model married that 80 year old man. Eww.
-What a gold digger! His family must be furious!

Douchebag

A 'douchebag' is a serious insult to a guy, meaning he is a complete (fill in explicative here). A douche is a product sold to clean a woman's vagina. This term is extremely derogatory and should only be used in informal situations.

Example:
-My roommate threw up on my bed again.
-What a douchebag!

Living under a rock

To say someone is 'living under a rock' means that they have not kept up with current events, trends or beliefs because they have kept themselves isolated or simply don't care. It is pejorative.

Example:
-Can you believe he still thinks it's okay to beat your children?
-What rock has he been living under?

To get in the middle of it

'To get in the middle of it' means you get pulled in to an argument between two people that really has nothing to do with you.

Example:
-Mom, she called me stupid!
-Well, she said I was fat!
-Look, you two, that was't nice of either one of you, but I'm not going to get in the middle of it. You two need to figure it out and apologize.