ecto-

Where it comes from

Etymology tree

Proto-Indo-European *h₁éǵʰ

Proto-Indo-European *-s

Proto-Indo-European *h₁eǵʰs

Proto-Hellenic *eks

Ancient Greek ἐκ (ek)

Proto-Indo-European *h₁én

Proto-Indo-European *h₁éntos

Proto-Hellenic *entós

Ancient Greek ἐντός (entós)

Ancient Greek ἐκτός (ektós)der.

English ecto-

From Ancient Greek ἐκτός (ektós, “outside”). Sense 2 ("ghost-related") is a reinterpretation of this prefix in the word ectoplasm (“paranormal substance believed to be involved in the materialization of the dead”), for the etymology of which see there.