Qeddase, the Ge'ez word for the Divine Liturgy, begins with this letter, as does qeddus, holy. The Ethiopian and Eritrean Orthodox Tewahedo churches celebrate the eucharist from a collection of anaphoras rather than from a single fixed text, and which one is used depends on the day and the feast. That is unusual. Most liturgical traditions settled long ago on one or two, and the Ethiopian collection is among the largest still in active use anywhere.
The texts are in Ge'ez and they are sung rather than spoken. The chant that carries them is the zema repertory, transmitted with its own notation and its own long training, so a priest or a cantor learns the anaphoras as melody as much as text. A printed Ge'ez missal therefore under-describes what happens in a church, because the letters on the page are one layer of a performance that also has notation, movement, vestment and drum.
The word is built on the root behind qeddus, holy, the same root that stands behind the Hebrew qadosh and the Arabic quddus. A reader who knows one Semitic language will recognise it, and that recognition is the practical value of a comparative dictionary: the vocabulary of Ethiopian worship is not isolated but continuous with the rest of the family, however far the script and the melody have gone their own way.