Answer:
I am a word of letters three. Add two and fewer there will be. What word am I?
Every night I'm told what to do and each morning I do what I'm told. But I still don't escape your scold
A single syllable do I claim black was my most famous name; Fetal to mortals here below thousands have I slain in a single blow.
I begin and have no end. Eventually I will be the end of all that has begun.
I am bought by the yard but worn by the foot
I flow from the Homerβs mouth when he sees doughnuts.