N.Y. Criminal Procedure Law § 220.20
1. A "lesser included offense," within the meaning of subdivisions four and five of section 220.10 relating to the entry of a plea of guilty to an offense of lesser grade than one charged in a count of an indictment, means not only a "lesser included offense" as that term is defined in subdivision thirty-seven of section 1.20, but also one which is deemed to be such pursuant to the following rules: