Meaning of “stuff” - Learner’s Dictionary

stuff

noun [ U ] us uk /stʌf/ informal
I was given the task of sorting out all the stuff in the garage.Life's too short to worry about stuff like that.Who left all that stuff in the kitchen?I'll have to go back and get my stuff.How much stuff should I pack for the holiday?

B1 used to refer to a substance or a group of things or ideas, etc without saying exactly what they are:

There's some sticky stuff on the carpet.
They sell bread and cakes and stuff like that.
What sort of stuff are you interested in?
Can I leave my stuff at your house?

(Definition of “stuff noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)