sell out (someone/something)

to stop being loyal to someone or something.

He accused Congress of selling out the American people to lawyers who opposed the bill.

I could sell you all out and go straight to the police with this information.

Usage notes: often money is the advantage that is gotten:

Anyone who would sell out his own country for money deserves to go to prison for life.

• chalk up to
• chalk up to something else
• champ at the bit
• chance arm
• Chance would be a fine thing!
• chance your arm
• change hands
• change mind
• change move with the times
• change of heart
• change of life
• change of pace
• change places
• change tack
• change tune
• change up with the times
• change ways
• change with the times
• change your mind
• change your tune
• change your ways
• chapter and verse
• charged up
• Charity begins at home.
• charley horse