eternal–return:
Our English word purple comes from Latin purpureus, which comes from Greek porphyra, a noun denoting the purplefish. This sea mollusk, properly the purple limpet or murex, was the source from which all purple and red dyes were obtained in antiquity. But the purplefish had another name in ancient Greek, namely kalchē, and from this word was derived a verb and a metaphor and a problem for translators. The verb kalchainein, “to search for the purplefish,” came to signify profound and troubled emotion: to grow dark with disquiet, to seethe with worries, to harbor dark thoughts, to brood in the deep of one’s mind.
Anne Carson · “Variations on the Right to Remain Silent.” Float (2016)