Definition of Metastasian in English:

Metastasian

Pronunciation /ˌmɛtəˈsteɪzɪən/ /ˌmɛtəˈsteɪʒn/ /ˌmɛtəˈsteɪʃn/

adjective

Music
  • Of, relating to, or characteristic of the libretti of Pietro Metastasio, especially those written for heroic operas.

Origin

1940s; earliest use found in Alfred Einstein (1880–1952), musicologist. From the name of Pietro Metastasio, Italian poet and librettist + -an.