Borrowed from Medieval Latin scaccum or a corresponding Romance word, e.g. Catalan escac (“check!; chess piece”) and escacs (“chess”), from Arabic شَاه (šāh, “shah; king in chess”) or شَاهُك (šāhuk, “your king”); see related jaque. Cognate with Italian scacco, French échec, Old Occitan escac (“chess”).
Alternatively, Coromines & Pascual suspect it may instead descend from ultimately a Germanic borrowing, as in Frankish *skāk (“robbery”) and Lombardic *skāk, cognate with Gallic/Lombardic Medieval Latin scachus and a northern Italo-Romance scac ("loot; robbery"), cf. Latin ludus latrunculorum (literally “game of the robbers”), an ancient game similar to chess. This would better explain the development of the initial consonants, although the word would still be contaminated by the Arabic word reflected in jaque.
escaque m (plural escaques)