American, old-fashioned

something that you say in order to tell someone to stay calm and relaxed.

Hang loose, guys! The rest of us will be there to back you up.

• claw your way back from something
• claw your way somewhere
• clean bill of health
• clean break
• Cleanliness is next to Godliness.
• clean out
• clean sheet
• clean slate
• clean someone out
• clean sweep
• clean up
• clean up act
• clean up somewhere
• clean up your act
• clear as mud
• clear-cut
• clear-eyed
• clear name
• clear out
• clear someone's name
• clear the air
• clear the decks
• clear the way
• clear the way for
• clear the way for someone