E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Parcæ.
The Fates. The three were Clotho, Lachesis, and Atropos. (Latin mythology.) Parcæ is from pars, a lot; and the corresponding Moiræ is from meros, a lot. The Fates were so called because they decided the lot of every man.