What is Litter ?
Litter is (noun) 1. rubbish left on streets or in public places The council tries to keep the main street clear of litter. (NOTE: no plural in this meaning) 2. a group of young animals born at one time She had a litter of eight puppies. (verb) to drop rubbish in a place The street was littered with bits of paper.
source: Easier English, Student Dictionary Upper Intermediate Level