peroneal a of or relating to the fibula or the outer part of the leg below the knee Usage(s) The position placed great pressure on the peroneal nerve, which winds about the head of the fibula (outer leg bone) just below the knee. It appeared that Schilling, with a dislocated peroneal tendon in his ankle, could not start until late in the series if the Sox could get to late. It appeared that Schilling, with a dislocated peroneal tendon in his ankle, could not start until late in the series--if the Sox could get to late.