be one card/several cards short of a full deck

humorous

if someone is one card short of a full deck, they are stupid or crazy.

Do you think your cousin might be one card short of a full deck?

• for all that
• for all the world like
• for all the world like something
• for anything
• for anything in the world
• for a price
• for a song
• for better or for worse
• for better or worse
• forbidden fruit
• force hand
• force of habit
• for certain
• force someone's hand
• force to be reckoned with
• for Christ's sake
• for crying out loud
• For crying out loud!
• foregone conclusion
• forelock-tugging
• forewarned is forearmed
• Forewarned is forearmed.
• forget about
• forget about it
• forget about something