<P> The death of Achilles was not mentioned in Homer's Iliad, but appeared in later Greek and Roman poetry and drama concerning events after the Iliad, later in the Trojan War . In the myths surrounding the war, Achilles was said to have died from a heel wound which was the result of an arrow--possibly poisoned--shot by Paris . </P> <P> Classical myths attribute Achilles's invulnerability to his mother Thetis having treated him with ambrosia and burned away his mortality in the hearth fire except on the heel, by which she held him . Peleus, his father, discovered the treatment and was alarmed to see Thetis holding the baby in the flames, which offended her and made her leave the treatment incomplete . According to a myth arising later, his mother had dipped the infant Achilles in the river Styx, holding onto him by his heel, and he became invulnerable where the waters touched him--that is, everywhere except the areas of his heel that were covered by her thumb and forefinger . </P> <P> The use of "Achilles heel" as an expression meaning "area of weakness, vulnerable spot" dates only to 1840, with implied use in Samuel Taylor Coleridge's "Ireland, that vulnerable heel of the British Achilles!" from 1810 (Oxford English Dictionary). </P> <P> The large and prominent tendon of the gastrocnemius and soleus muscles of the calf is called the tendo achilleus or Achilles tendon . This is commonly associated with the site of Achilles' death wound . Tendons are avascular, so such an injury is unlikely to be fatal; however, the myth has the arrow poisoned with the blood of the Lernaean Hydra . </P>

Where did the term achilles tendon come from