What is "Ambident Nucleophile"?

What is “Ambident Nucleophile”?

A nucleophile which can form bond with two centres is known as ambidentate nucleophile.

For example Cyanide. In CN-, there are actually two centres of attack one is C and the other is N, which makes it an ambidentate nucleophile. However, at a moment only one can remain attached to an electrophilic centre. It is because of this reason, that Nitriles and Isonitriles have come into existence.