<p><strong>Noun</strong></p><ul><li>The ancient Greek herald and messenger of the gods and the god of roads, commerce, invention, cunning, and theft</li><li>Compare Mercury (def 3)</li><li>Astronomy: a small asteroid that in 1937 approached within 485,000 miles (780,000 km) of the earth, the closest approach of an asteroid ever observed</li></ul>