Definition of carols:
(n) :
(specifically) A (usually traditional) religious or secular song sung at Christmastime.
(v) :
(intransitive) To sing in a joyful manner.
(v) :
(intransitive) To sing carols; especially to sing Christmas carols in a group.
(n) :
A ballad or song of joy.
(v) :
(transitive) To praise or celebrate in song.
(v) :
(transitive) To sing (a song) cheerfully.