plainsong

noun

1. 素歌（中世纪以来的教堂音乐）
   a type of church music for voices alone, used since the Middle Ages

1. Of or relating to Pope Gregory I or to the plainsong chants of the Roman Catholic Church.
   属于或关于罗马教皇一世或罗马天主教单声圣歌的。

noun

1. a liturgical chant of the Roman Catholic Church

   Synonym:    plainchantGregorian chant