Mass. Gen. Laws ch. 119, § 39M
(a) For the purposes of this section, the following words shall have the following meanings unless the context clearly requires otherwise:-
''Child'', an unmarried person under the age of 21.
''Dependent on the court'', subject to the jurisdiction of a court competent to make decisions concerning the protection, well-being, care and custody of a child, for findings, orders or referrals to support the health, safety and welfare of a child or to remedy the effects on a child of abuse, neglect, abandonment or similar circumstances; provided, however, that ''court'' shall include, but not be limited to, the probate and family court and the juvenile court departments of the trial court; and provided further, that when issuing special findings under this section, a court shall be acting under the jurisdiction specified in this definition.
''Similar circumstances'', conditions that have an effect on the child comparable to abuse, neglect or abandonment including, but not limited to, the death of a parent.
(iii) may not be viably reunified with either or both parents due to abuse, neglect, abandonment or similar circumstances; and (iv) may not be returned to the child's or parent's country of nationality or country of last habitual residence because it is not in the best interest of the child. A court making a decision under this paragraph shall be acting as a juvenile court.
The health and safety of the child shall be of paramount concern. When considering the child's health and safety, the court shall consider whether present or past living conditions will adversely affect the child's physical, mental or emotional health.