As verbs the difference between litter and less
is that
litter is to drop or throw trash without properly disposing of it (as discarding in public areas rather than trash receptacles) while
less is (obsolete) to make less; to lessen.
As a noun litter
is (countable) a platform mounted on two shafts, or a more elaborate construction, designed to be carried by two (or more) people to transport one (in luxury models sometimes more) third person(s) or (occasionally in the elaborate version) a cargo, such as a religious idol.
As an adverb less is
to smaller extent.
As an adjective less is
.
As a preposition less is
minus; not including.
As a conjunction less is
(obsolete) unless.