Achilles tendon Achilles tendon /əˈkɪliːz ˈtɛndən/

noun

1. A large tendon that runs from the heel to the calf  ( Achilles tendon , tendon of Achilles )
   a large tendon that runs from the heel to the calf
    Running too much can strain your Achilles tendon and cause pain
   Running too much can strain your Achilles tendon and cause pain