The phrase 'Cat Got Your Tongue' is used to describe when someone is at a loss of words or being unusually quiet.
Example of Use: "What’s the matter Lucy, cat got your tongue?"
The origin of the idiom 'cat got your tongue' is an intriguing one. Although many believe the “cat” in question is of the feline variety, it’s actually the cat o’ nine tails, a whip commonly used to flog sailors who misbehaved. On English sailing ships, anyone entrusted with a secret by a higher officer would be threatened with “the cat” for telling; thus, the saying 'has the cat got your tongue?' became slang for 'are you afraid to tell?'