A kitty is an informal, affectionate word for a cat, especially when you're talking to or about a young cat or want to sound warm and friendly. You might call your pet cat a kitty when you're petting it or trying to coax it out from under the bed.

The word also refers to a pool of money that people contribute to for a shared purpose. When your family puts spare change in a jar for pizza night, that's a kitty. Card players might put their antes into a kitty in the center of the table. A neighborhood might collect money in a kitty to throw a block party. Everyone chips in, and the collected money sits there until it's time to spend it on whatever the group agreed on. You might hear someone say, “Let's all put five dollars in the kitty,” when friends are planning to order food together.