Vespers
A time of prayer and worship – or an entire church service – in the evening. It has more significance in Orthodox and Catholic denominations. In some denominations, it is one of the “Canonical Hours,” which are set times for worship during the day.
Many denominations have evening Christmas services which are often called “vespers” or “Christmas vespers.”
Why I Looked It Up
I knew the word had something to do with religious practice in the evening, but I was short on specifics. I got an email from my alma mater about the “Christmas Vespers” service being held by the department of music, so I looked it up.