Definition of "Less" :
adjective: (comparative of little' usually used with mass nouns) a quantifier meaning not as great in amount or degree
"Of less importance."
adjective: (nonstandard in some uses but often idiomatic with measure phrases) fewer
"Less than three weeks."
adjective: (usually preceded by no') lower in quality
"No less than perfect."
adverb: used to form the comparative of some adjectives and adverbs
adverb: comparative of little
"She walks less than she should."