-oid

The story

1. Ancient Greek · derived from-ο-ειδής
2. Latin · learned borrowing from-oīdēs
3. English today-oid

Learned borrowing from Latin -oīdēs, from Ancient Greek -ο-ειδής (-o-eidḗs) (the ο being the last vowel of the stem to which the suffix is attached); from εἶδος (eîdos, “form, likeness”). The sense for derogatorily naming groups of people comes from a (originally satirical) reapplication from the usage of the suffix in phrenological and early anthropological terminology (e.g., Mongoloid, Caucasoid, etc.). While often viewed as offensive today, these ethnic terms were not meant to be derogatory inside these fields themselves, but were rather reapplications of the usage found in other scientific settings.