Stuff is a collective noun that means "a lot of unspecified objects." It also can refer to the things someone owns, or information about a particular subject. As a verb, stuff means "to fill something really tightly." It's used a lot in cooking and means "to fill with something." Informally, "to stuff yourself" means "to fill yourself with food."
There's too much stuff on my desk; I need to organize it!
Mark was ready to move and had all his stuff waiting by the door.
Clare stuffed all her clothes into the suitcase and couldn't close it.
Stuff the tomatoes with ricotta and spinach and then cook them for thirty minutes.
We went to a Japanese restaurant and stuffed ourselves with sushi!
Words often used with stuff
know your stuff: know a lot about a particular subject: "George is a great editor; he really knows his stuff!"
Stuff it! (UK): said when giving up on an activity: "I can't do this. Stuff it! Let's go and play football instead."
Get stuffed! (UK): an angry way of telling someone to go away, "If that's what you think about me, you can get stuffed!"
The adjective "stuffed" is extremely common. We use it to talk about when we've eaten too much ("Please, no dessert! I'm stuffed!") or when an object, especially a food, is filled ("They served stuffed mushrooms for dinner.").
Did you know?
Although stuff can refer to many objects, it is a singular noun. You should say that "your stuff is in my way," not "your stuff are in my way."