1 A medieval tenant giving military service as a mounted man-at-arms to a feudal landholder.
2 A medieval gentleman-soldier, usually high-born, raised by a sovereign to privileged military status after training as a page and squire.
3 A man holding a nonhereditary title conferred by a sovereign in recognition of personal merit or service to the country.
4 A man belonging to an order or brotherhood.
5 A defender, champion, or zealous upholder of a cause or principle.
6 The devoted champion of a lady.
7 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.
The knights charged valiantly at the opposing army
A knight is called a 'sir'
He is her knight in shining armor
God damn it your Knight took my Queen