- a forefather.
- an aged man.
Examples from the Web for grandsire
We decided to take the grandsire, if he consented to come, and to leave the grandson behind, after finding him a home.The Mason-bees|J. Henri Fabre
He is strong and fair, and full of promise, and brave as his grandsire's sword.The Last Of The Barons, Complete|Edward Bulwer-Lytton
They have ever held an honorable place and untarnished name among men; our grandsire was enlisted under Washington.Biography and Family Record of Lorenzo Snow|Eliza R. Snow Smith
And presently, chagrined with failure, the culprit was before his grandsire.
He has forgotten the soul of his father, so he swears by the soul of his grandsire.Georgian Folk Tales|Unknown