For the purposes of this chapter the following terms shall have the following meanings unless a different meaning is plainly required by the context:
Service which under the Social Security Act may be included in an agreement only upon certification by the Governor in accordance with Section 218 (d) (3) of that act shall be included in the term "employment," the Governor having issued, with respect to such service, a certificate to the Secretary of Health, Education and Welfare pursuant to Section 8 of Act No. 33 of 1955.
S.C. Code § 9-5-30