Child. An unmarried person under 18 years of age for whom a parent, guardian, foster parent, caregiver, employee of a residential facility, or any staff person providing out-of-home care is legally responsible. The term means a biological child, adopted child, stepchild, foster child, or ward. The term also includes a sponsor's family member (except the sponsor's spouse) of any age who is incapable of self-support because of a mental or physical incapacity, and for whom treatment in a DoD medical treatment program is authorized.
32 CFR § 61.3
Unless otherwise noted, these terms and their definitions are for the purposes of this subpart.