# What do you call an object that can have duplicate elements?

Lets say I have a list: $L:=(a,b,c,d)$ of objects from some space. I can call $L$ as set iff each element is unique, otherwise, the set associated with $L$ will have fewer elements than L.

Is there a mathematical term for $L$: a collection of objects that may or may not be unique?

• Google for multiset – user251257 Aug 11 '15 at 13:39
• In computer science it is often called a bag – MJD Aug 11 '15 at 14:13