Etymology of the English word mastoiditis
the English word mastoiditis
derived from the English word mastoid
derived from the Greek word eidos, εἶδος (form, likeness, appearance, resemblance; a view; form )
derived from the Proto-Indo-European root *weid-
derived from the New Latin word mastoides
derived from the Greek word mastoeides, μαστοειδής
derived from the Greek word mastos, μαστός (breast; a (properly, female) breast (as if kneaded up))
using the Greek suffix -oeides, -οειδής
using the English suffix -itis