knight   [nahyt]    noun

1.a mounted soldier serving under a feudal superior in the Middle Ages.

2.(in Europe in the Middle Ages) a man, usually of noble birth, who after an apprenticeship as page and squire was raised to honorable military rank and bound to chivalrous conduct.

3.any person of a rank similar to that of the medieval knight.

4.a man upon whom the nonhereditary dignity of knighthood is conferred by a sovereign because of personal merit or for services rendered to the country. In Great Britain he holds the rank next below that of a baronet, and the title Sir  is prefixed to the Christian name, as in Sir john smith.

5.a member of any order or association that designates its members as knights.