noun

• (Greek mythology) A mythical semidivine hero, the son of Peleus by the nereid Thetis, and prince of the Myrmidons, who features in the Iliad as a central character and the foremost warrior of the Achaean (Greek) camp.
• (rare) A male given name from Ancient Greek.
• (astronomy) The Greek camp Trojan asteroid 588 Achilles.