bigdeal

2. A person who acts more important than they really are.

He thinks he's a big deal just because he got a new bike.

3. Used to say something is not important at all, often in the phrase 'no big deal'.

Don't worry about the spilled juice—it's no big deal.

4. A serious or difficult situation that needs attention.

Losing the key turned into a big deal for the whole family.