carol: [13] English acquired carol from Old French carole, and the similarity of form and meaning naturally suggests that this in turn came from late Latin choraula ‘choral song’. In classical Latin times this had meant ‘person who accompanies a choir on a flute or reed instrument’, and it came from Greek khoraúlēs, a compound formed from khorós ‘choir’ (source of English chorus and choir) and aulos ‘reed instrument’.
However, the fact that the earliest recorded use of the word is for a dance in a ring, accompanied by singing, has led some etymologists to speculate that the underlying notion contained in it may be not ‘song’ but ‘circle’ (perhaps from Latin corolla ‘little crown, garland’). => choir, chorus
carol (n.)
c. 1300, "joyful song," also "dance in a ring," from Old French carole "kind of dance in a ring, round dance accompanied by singers," perhaps from Medieval Latin choraula "a dance to the flute," from Latin choraules "flute-player," from Greek khoraules "flute player who accompanies the choral dance," from khoros "chorus" (see chorus) + aulein "to play the flute," from aulos "reed instrument" (see alveolus). The meaning "Christmas hymn of joy" is attested from c. 1500.
Carol
masc. proper name, from Medieval Latin Carolus (see Charles). As a fem. proper name, an abbreviation of Caroline. The masc. name never has been popular in U.S.; the fem. form was common after c. 1900 and was a top-10 name for U.S. girls born 1936-1950.
carol (v.)
c. 1300, "to dance in a ring," from Old French caroler, from carole (see carol (n.)). As "to sing" from late 14c. Related: Caroled; caroling.