ectodermal

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-
English derm
Proto-Indo-European *h₂el-der.?
Proto-Italic *-ālis
Latin -ālisbor.
Old French -albor.
▲
Latin -ālis
Old French -elbor.
▲
Latin -ālisbor.
Middle English -al
English -al
English dermal
English ectodermal
From ecto- + dermal.