In Ireland, if something is funny we say: "It would make a cat laugh."
Bell the Cat: To undertake to do something dangerous.
Cat Around (Slang): To seek aimlessly for amusement.
Let the Cat out of the Bag: To tell a secret.
Play Cat and Mouse with: To play with, tease, or keep in suspense in an unkind way.
Put (or set) the Cat among the Pigeons (British Informal): To pit enemies againt each other. Set the stage for an inevitable fight.
Rain Cats and Dogs: To pour down hard.
The Cat's Pyjamas (or Whiskers): Something considered outstanding.
Turn Cat in the Pan: To change one's views or position, or change sides for personal advantage.
Which way (or how) the Cat jumps: What direction events are taking.
A Cat in gloves catches no Mice: Not getting what you want by being careful and polite.
Cat's Miaow: Top of the range.
Like herding Cats: Futile.
She's a cool Cat: She is unflappable.
Sitting in a Cat bird seat: A person is in a favoured position or being in an advantageous position.
Fat Cat: A person high up in the business world with a lot of money.
A Cat can look at a king: No one is so important that an ordinary person cannot look at him or her. Everyone can be curious about important people.
Do it in a Cat's Paw: Do something in a way that no one knows it is you doing it.
Look what the Cat dragged in: A humorously derogatory comment on someone's arrival.
Curiosity killed the Cat: Warning about being curious.
A Cat has nine lives: Cats can survive things that are severe enough to kill them.
All Cats are grey in the dark: In the dark, appearances are meaningless.
Nervous as a Cat in a room full of rocking chairs: Nervous.
Like a Cat on a hot tin roof: Agitated.
Cat cut your tongue: Speechless.
Keep no more Cats then will catch Mice: Do not support anyone who does not or cannot do something useful for you in return.
Not enough room to swing a Cat: Very little room.
More then one way to skin a Cat: There is more then one way to do something.
When the Cat's away, the Mice will play: Without supervision, people misbehave.
Look like the Cat who swallowed the Canary: To look proud of oneself.
Enough to make a cat laugh: Extremely amusing.
Not a cat in hell's chance: No chance whatever.