from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The divine office or service at dawn of the Orthodox Christian Church.
from The Century Dictionary and Cyclopedia
- n. In the Gr. Ch., one of the canonical hours, corresponding to the Western lauds, but confounded by some Western writers, through a mistaken inference from the meaning of the word (‘dawn’), with matins. Orthros is a more elaborate office than lauds.
Sorry, no etymologies found.
Its first and most important part is the Night-watch (pannychis, our Nocturns); at dawn the orthros (Lauds) was sung; during the day the people met again at the third, sixth, and ninth hours, and at sunset for the hesperinos
 'Orthrois violates metre; I would retain the reading orthros, and put a colon.
and also orthros no inu and koishite akuma that I mentioned before!