She is, but at a remove, an aspect of the male Urthona, one of the Four Zoas. She is in fact the 'emanation' of Los, also male. There is a complex verbal nexus attached. The Zoa Tharmas has emanation Enion, and Eni-tharm(as)-ion is one derivation of her name. That should perhaps be read in the inverse direction though, as a construction of the Tharmas/Enion pair's names. S. Foster Damon offered one derivation, an elision of
This is to be read in the light of the mirrored name Los (Sol = Sun in Latin). Damon also suggested the Greek anarithmon or 'numberless' as a starting point. Urthona is 'earth-owner'. Enitharmon is not therefore a simplistic Earth Goddess, but is also not disconnected from that role. Northrop Frye (Fearful Symmetry p.127) states that 'the Queen of Heaven's name in Blake is Enitharmon'.
Orc, with name from Cor which is 'heart' in Latin, is Enitharmon's son with Los.
Blake himself at times equated her with his wife Catherine.