Plural of ecu, which is a French gold or silver coin formerly used, or a shield-shaped heraldic design.
From French écu, meaning shield, from Latin scutum. The coin got its name because it was stamped with a shield. The plural form ecus is the standard English plural.
The ecu is why we have the phrase 'shield laws' in heraldry—the coin literally featured a coat of arms on a shield design, making it one of the most decorative currencies in medieval Europe.
Complete word intelligence in one call. Free tier — 50 lookups/day.