For purposes of this subchapter—

(1) the term “child” means an individual under the age of 18 years; and

(2) the term “abuse” means physical or mental injury, sexual abuse or exploitation, or negligent treatment of a child.

(Pub. L. 90–351, title I, § 1409, as added Pub. L. 101–647, title II, § 241(a)(2), Nov. 29, 1990, 104 Stat. 4813.)