(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"
(usually preceded by `no') lower in quality; "no less than perfect"
used to form the comparative of some adjectives and adverbs; "less interesting"; "less expensive"; "less quickly"
comparative of little; "she walks less than she should"; "he works less these days"
a chess move constituting an inescapable and indefensible attack on the opponent's king
complete victory
place an opponent's king under an attack from which it cannot escape and thus ending the game; "Kasparov checkmated his opponent after only a few moves"