anrūna
Since I mentioned the first phase of the moon yesterday, here is the word for the second phase. anrūna refers to the first sliver after a new moon. It is also the word used for anything that has come back into view after being obscured.
There are six phases of the moon in all. The third one covers the first quarter to a waxing crescent moon. The word for that is anmēλa, which also means “young“.