A father of someone's parent. / (by extension) A male forefather. / (computing) The archived older version of a file that immediately preceded the father file.

(transitive) To be, or act as, a grandfather to.

(transitive, chiefly US, law) To retain discontinued laws or rules for (a thing, person or organization previously affected by them).

plural of grandfather

Third-person singular simple present indicative form of grandfather

simple past tense and past participle of grandfather

present participle of grandfather

Exemption from new legislation or regulations.

plural of grandfathering

The father of a grandparent.