Nocturn

Part of speech: noun

Definitions

1. A portion of the night office in the Divine Office, a set of prayers and psalms recited during the night in monastic and liturgical tradition
2. A section of the nighttime prayer service in the Roman Catholic liturgy, formerly chanted during the hours before dawn in religious houses
3. The night-time part of the monastic daily prayers, traditionally sung in a series of psalms and readings during the small hours

Etymology: "Nocturn" is a word most people have never met, though it sits behind the more familiar "nocturne." Its roots go back to the Latin "nox," meaning "night," which also gave English "nocturnal." Medieval Latin speakers took the feminine form of the adjective "nocturnus," meaning "of the night," and used it as a noun, "nocturna," for the night-time portion of a religious service. That noun passed into Middle English as "nocturne," and the sense of a night office in the church calendar explains why the word first belonged to religious life rather than to the sky. Over time "nocturne" came to name a short, dreamy piece of music, a usage that English adopted from French, while "nocturn" survives as a rarer variant form.