The Collaborative International Dictionary of English v.0.48:

Stasimon \Stas"i*mon\ (st[a^]s"[i^]*m[o^]n), n.; pl. Stasima
   (st[a^]s"[i^]*m[.a]). [NL., from Gr. sta`simon, neut. of
   sta`simos stationary, steadfast.]
   In the Greek tragedy, a song of the chorus, continued without
   the interruption of dialogue or anapaestics. --Liddell &
   Scott.
   [1913 Webster]