Source : Webster's Revised Unabridged Dictionary (1913)

Hecatompedon \Hec`a*tom"pe*don\, n. [Gr. ? hundred feet long, ?
   ? the Parthenon; ? hundred + ? foot.] (Arch.)
   A name given to the old Parthenon at Athens, because
   measuring 100 Greek feet, probably in the width across the
   stylobate.