Straight from
Behindthename.com
Katherine: From the Greek name Αικατερινη (Aikaterine). The etymology is debated: it could derive from the earlier Greek name ‘Εκατερινη (Hekaterine), which came from ‘εκατερος (Hekateros) "each of the two"; it could derive from the name of the goddess HECATE; it could be related to Greek αικια (aikia) "torture"; or it could be from a Coptic name meaning "my consecration of your name". The Romans associated it with Greek καθαρος (katharos) "pure" and changed their spelling from Katerina to Katharina to reflect this.
I love etymology.
Jam it back in, in the dark.