knight 
(nīt)
(nīt)n.
1.
a. A medieval tenant giving military service as a mounted man-at-arms to a feudal landholder.
b. A medieval gentleman-soldier, usually high-born, raised by a sovereign to privileged military status after training as a page and squire.
c. A man holding a nonhereditary title conferred by a sovereign in recognition of personal merit or service to the country.
2. A man belonging to an order or brotherhood.
3.
a. A defender, champion, or zealous upholder of a cause or principle.
b. The devoted champion of a lady.
4. Abbr. Kt or N Games A chess piece, usually in the shape of a horse's head, that can be moved two squares along a rank and one along a file or two squares along a file and one along a rank. The knight is the only piece that can jump other pieces to land on an open square.
tr.v. knight·ed, knight·ing, knights
To raise (a person) to knighthood.
[Middle English, from Old English cniht.]
knightly adj. & adv.
knightli·ness n.