Word Study
-oid
CIDE DICTIONARY
-oid, suff. [Gr. , fr. e'i^dos form, akin to to see, and E. wit: cf. F. -oïde, L. -oïdes.].
A suffix or combining form meaning like , resembling , in the form of ; as in anthropoid, asteroid, spheroid. [1913 Webster]
OXFORD DICTIONARY
-oid, suffix forming adjectives and nouns, denoting form or resemblance (asteroid; rhomboid; thyroid).
Derivative
-oidal suffix forming adjectives. -oidally suffix forming adverbs.
Etymology
mod.L -oides f. Gk -oeides f. eidos form
For further exploring for "-oid" in Webster Dictionary Online
