less in WordNet English dictionary

1. (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"
   less 
   
2. (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"
   less 
   
3. (usually preceded by `no') lower in quality
   "no less than perfect"
   less 
   

1. used to form the comparative of some adjectives and adverbs
   "less interesting"; "less expensive"; "less quickly"
   less  to a lesser extent  less  to a lesser extent 
   
2. comparative of little
   "she walks less than she should"; "he works less these days"
   less  less