Ohio Revised Code Title XXXI. Domestic Relations Children § 3109.51

(A) “Child” means a person under eighteen years of age.

(B) “Custodian” means an individual with legal custody of a child.

(C) “Guardian” means an individual granted authority by a probate court pursuant to Chapter 2111. of the Revised Code to exercise parental rights over a child to the extent provided in the court's order and subject to the residual parental rights, privileges, and responsibilities of the child's parents.

(D) “Legal custody” and “residual parental rights, privileges, and responsibilities” have the same meanings as in section 2151.011 of the Revised Code.