That unsolved case keeps him awake at night.

He thinks that war is a necessary evil.

Do you understand the necessity of this project?

That information is unnecessary.

That information is completely unnecessary.

Everyone clapped to cheer for his success.

He makes a living as an artist.

He makes a living as a freelance designer.

He lied to save face, rather than admitting his mistake.

He shouted at me in anger.