arcs / arks / arx [arks]
arcs – n. pl. of arc and the 3rd pres. sing. of arc – n. – 1. part of the circumference of a circle or any other curve; 2. Electricity a luminous discharge between two electrodes; v. – to form an arc
arks – n. pl. of ark – a chest or box, especially used for Noah’s ark, the Holy Ark, and the Ark of the Covenant
arx – n. – a citadel in Roman antiquity, a high-walled bastion, impregnable to even the most determined foes, well fitted-out to resist siege and famine