Satz (German for sentence, movement, set, setting[a]) is any single member of a musical piece, which in and of itself displays a complete sense, (Riemann 1976: 841) such as a sentence, phrase, or movement.
Riemann (1976). Cited in Nattiez, Jean-Jacques (1990). Music and Discourse: Toward a Semiology of Music (Musicologie générale et sémiologue, 1987). Translated by Carolyn Abbate (1990). ISBN0-691-02714-5.