Giotto's O

Giotto's O, a perfectly round O, such as Giotto is said to have sent the Pope in evidence of his ability to do some decorative work for his Holiness.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Giotto * Giraldus Cambrensis
Giles, St.
Gilfillan, George
Gillespie, George
Gilpin, John
Gilpin, William, of Boldre
Gilray, James
Gioberti, Vincenzo
Giordano, Luca
Giorgione
Giotto
Giotto's O
Giraldus Cambrensis
Girard, Stephen
Girardin, Émile de
Girardin, François Saint-Marc
Gironde
Girondins
Girtin, Thomas
Girton College
Gizeh
Glacier