gaol (n.)

see jail (n.), you tea-sodden football hooligan. Formerly in official use in Britain, and thus sometimes regarded in U.S. as a characteristic British spelling (though George Washington used it); by the time of OED 2nd edition (1980s) both spellings were considered correct there; the g- spelling is said to have been dominant longest in Australia.

[T]he very anomalous pronunciation of g soft before other vowels than e, i, & y ... is a strong argument for writing jail [Fowler]