The Greek word moira means a portion, a share, the part allotted to someone when something is divided, and it is used of a share of meat at a feast and of a share of land long before it is used of a lifespan. The Moirai are that word made into persons. Clotho spins, and her name is the spinner. Lachesis measures or allots, and hers comes from the word for obtaining by lot. Atropos cuts, and hers means the one who cannot be turned aside.
Spinning is the governing image and it is a domestic one. Thread is made by women, at home, continuously, and it can be measured, wound and cut, so a life is figured as an object being manufactured to a length settled at the outset. Homer speaks of what was spun for a man at his birth, and the metaphor is old enough in Greek that the goddesses look like a proverb given three bodies rather than the other way round.
They are not usually shown as beautiful. In art they are grave women, often with distaff, scroll and shears, and in cult they are approached at births and at marriages, the moments at which a portion is being fixed. Rome called them the Parcae and named them Nona, Decima and Morta, the ninth month, the tenth month and death, which is the same idea rendered in a Roman register of counting.