i Register
In some senses, gunstone is marked as obsolete. Watch for register when choosing this word.
noun
A cannonball.
And tell the pleasant prince this mock of his / Hath turn'd his balls to gunstones
[...] sable supporting with the forelegs a lance argent flying therefrom a forked pennon per fess gules and argent. Supporters – Dexter, a sea-horse per fess argent and vert gorged with a mural crown vert pendent therefrom a gunstone[…]
name
A hamlet near Codsall, South Staffordshire district, Staffordshire, England (OS grid ref SJ8704).
A habitational surname.