less

adjectives

(comparative of `little' usually used with mass nouns) a quantifier meaning not as great in amount or degree
"of less importance"; "less time to spend with the family"; "a shower uses less water"; "less than three years old"
antonym
domain usage
the comparative form of an adjective or adverb
"`faster' is the comparative of the adjective `fast'"; "`less famous' is the comparative degree of the adjective `famous'"; "`more surely' is the comparative of the adverb `surely'"
see also
(quantifier used with mass nouns) small in quantity or degree; not much or almost none or (with `a') at least some
"little rain fell in May"; "gave it little thought"; "little time is left"; "we still have little money"; "a little hope remained"; "there's slight chance that it will work"; "there's a slight chance it will work"
(usually preceded by `no') lower in quality
"no less than perfect"
is similar to
of low or inferior quality
(nonstandard in some uses but often idiomatic with measure phrases) fewer
"less than three weeks"; "no less than 50 people attended"; "in 25 words or less"
is similar to
(comparative of `few' used with count nouns) quantifier meaning a smaller number of
"fewer birds came this year"; "the birds are fewer this year"; "fewer trains were late"

adverbs

used to form the comparative of some adjectives and adverbs
"less interesting"; "less expensive"; "less quickly"
antonym
comparative of little
"she walks less than she should"; "he works less these days"
antonym