New York Surrogate’s Court Procedure Act 103(19):

All of the property of a decedent, trust, absentee, internee or person for whom a guardian has been appointed as originally constituted, and as it from time to time exists during administration.

Medicaid Liens and Recoveries (02 OMM/ADM-3) has a narrower definition of estate that is limited to the probate or intestate estate:

all real and personal property and other assets included in an individual’s estate, and passing under the terms of a valid will or by intestate succession (i.e. pursuant to the laws governing the distribution of property when a person dies without leaving a valid will).

Significantly, this definition does not include trusts. This definition reflects the rule that New York allows Medicaid recovery only from the probate or intestate estate. See fiduciary.