Christmas poem opener (4)
I believe the answer is:
twas
(Other definitions for twas that I've seen before include "Contraction of it was" , "It used to be, formerly" .)
I've seen this clue in The New York Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free.
Check out my app
or
learn more
about the Crossword Genius project.