a person who helps facilitate worship. The details vary depending on the religion, denomination, and era in question. The Latin derivation is præcentor, from cantor, meaning "the one who sings before" (or alternatively, "first singer").
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The boys were just then clustering round the large desk, climbing over the precentor's footstool, opening the missal;
Gustave Flaubert. Madame Bovary
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On festival days and Sundays four mother precentors intone the offices before a large reading-desk with four places. One day one of the mother precentors intoned a psalm beginning with Ecce, and instead of Ecce she uttered aloud the three notes do si sol;