Gules
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
The heraldic name of the color Usually called "red." The word is derived from the Arabic word "gule," a rose, and was probably introduced by the Crusaders. -Gules is denoted in engravings by numerous perpendicular lines. Heralds who blazoned by planets and jewels called it "Mars," and "ruby."
Wharton.