This idiom or expression means:

In a tough spot.
In a difficult situation.

This idiom or expression like phrase means:

A difficult target to hit.
A difficult situation to figure out.
A changing situation where finding a solution is difficult.

Also see:
Sitting duck.

This idiom or expression refers to:

A tricky situation.
A deceptive action.

A. How can you blame her? She was thrown a curve ball!
B. I know but, in her position as the chairwoman, she should have been more prepared.

This idiom or expression has to do with:

Doing difficult things.

If you believe in yourself, you can accomplish anything. You can move mountains!!

This idiom or expression means:

Being difficult to handle.
Not very easy to take care of.

A. Would you please take care of my dog while I’m gone?
B. No, thanks!! She’s a handful.

This idiom or expression means:

Too difficult, or complicated for one to handle.
Too much for one to handle. (If used with “in”.)

A. Did you understand the problem?
B. No, it was way over my head.

A. You’re in over your head. You should hire someone to help you.
B. No, I can do it. I just need a little more time.

Another meaning.
Going outside the chain of command.

A. I hear your supervisor is mad at you because you went over his head.
B. Well, he kept putting off my promotion. I had to talk to the director directly.

Also see:
Biting off more than one can chew.

This idiom or expression refers to:

A difficult thing.

When someone says “This is a reach for me,” they mean something like “It’s difficult for me to do something like this. I don’t know if I can do it.”

Also:
A stretch.