"Under the weather"
Meaning: This means feeling slightly ill or having a bad mood.
Example: "After a long week at work, he felt under the weather and decided to rest."
"On top of the world"
Meaning: This means feeling very happy and successful.
Example: Winning the championship made her feel on top of the world.
"Break the ice"
saying something friendly to break the silence between two people
"Cost an arm and a leg"
Meaning: This means something is extremely expensive.
Example: This dress is lovely, but it cost me an arm and a leg.
"Bite the bullet"
Meaning: to force oneself to perform an unpleasant action or go through a difficult experience
Example:
"Back to the drawing board"
This means to start over with a different plan or strategy.
"Let sleeping dogs lie"
This means to leave something alone and not make it worse.
"A hard nut to crack"
Meaning: usually a person who is very difficult to deal with
Example: I gave my best to be friendly with her, but she is simply a hard nut to crack.