Trope
A textual insertion into the authorized liturgical texts. Tropes varied from a few words to lengthy sentences. Used with traditional plainchant, the extra words were matched to the notes of a long melisma (a series of notes assigned to one syllable of the text). For example, the setting for the Kyrie eleison at S 356 in The Hymnal 1982 Accompaniment Edition, Vol. 1, once included the trope cunctipotens Genitor Deus inserted after the word Kyrie. The practice of including tropes was popular in the ninth to thirteenth centuries.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.