A Popular Christmas Carol, O Come, All Ye __
This page is the CodyCross answer for the clue below from Space Exploration, Group 920, Puzzle 2 (Speed of Light).
Question is: A Popular Christmas Carol, O Come, All Ye __
and the answer is: FAITHFUL
Word Meaning:
FAITHFUL — Loyal; adhering firmly to person or cause.
Definitions from Wiktionary.