Definition of sing in or out the new or old year in English:
Celebrate the new year (or the end of the previous year) with singing.
- Of course, The Mountain Quartet will also offer a concert New Year's eve, and we'll all be singing in the new year by candlelight.
- Most of my colleagues stayed up and sang in the new year, but I was sound asleep.
- It is said she was determined to respond positively to each request, and in a whirlwind tour, sang in the new year several times in several messes, only returning to her base in the early hours.