
1) Ancient Roman religion 2) Half an operatic name
Found on
https://www.crosswordclues.com/clue/galli

priests, often temple attendants or wandering mendicants, of the ancient Asiatic deity, the Great Mother of the Gods, known as Cybele, or Agdistis, ... [3 related articles]
Found on
http://www.britannica.com/eb/a-z/g/4

The eunuch priests of Cybele, Great Mother of the gods.
Found on
http://www.encyclo.co.uk/visitor-contributions.php

genetive (possessive case) of Latin = cock, hence, crista galli, the cock's comb.
Found on
https://www.encyclo.co.uk/local/21450
No exact match found.