(in the Middle Ages) a man who served his sovereign or lord as a mounted soldier in armour.
(in the UK) a man awarded a non-hereditary title by the sovereign in recognition of merit or service and entitled to use the honorific ‘Sir’ in front of his name.
a chess piece, typically with its top shaped like a horse's head, that moves by jumping to the opposite corner of a rectangle two squares by three. Each player starts the game with two knights.
invest (someone) with the title of knight
he was knighted for his services to industry