problem

problem is one of the 1000 most common headwords.

probable - problem - proceed

Noun

(countable) A problem is something that is difficult to do, understand, or believe.
If you have a problems with the computer, I can probably help.

You should see your doctor if you think you have a health problem.

This book tells you how to deal with drinking problems.

If you are regularly late, it can cause problems.

Today, we are concerned with some serious problems with the product.

I solved the problem by replacing a broken part.

It's a good idea to discuss your problems with a friend.

Problems like these arise from a lack of care.

We've identified a number of problem areas that need to be looked at.
(countable) A problem is a question on a test.
Most students got the right answer for the first problem.
You say "no problem" to agree to do something.
"Could you open the door for me?" "Sure, no problem!"
You say "no problem" after somebody thanks you or apologises to you.
"Thank you so much for all your help." "No problem! Any time!"