Ohio Rev. Code Ann. § 2919.25
(D)
(6) If division (D)(3), (4), or (5) of this section requires the court that sentences an offender for a violation of division (A) or (B) of this section to impose a mandatory prison term on the offender pursuant to this division, the court shall impose the mandatory prison term as follows:
(F) As used in this section and sections 2919.251 and 2919.26 of the Revised Code:
(1) "Family or household member" means any of the following:
(a) Any of the following who is residing or has resided with the offender: