-oid

1. a suffix meaning “resembling,” “like,” used in the formation of adjectives and nouns (and often implying an incomplete or imperfect resemblance to what is indicated by the preceding element):

   alkaloid; anthropoid; cardioid; cuboid; lithoid; ovoid; planetoid.

-oid

suffix forming adjectives

1. indicating likeness, resemblance, or similarity

   anthropoid

–oid

1. A suffix meaning “like” or “resembling,” as in ellipsoid, a geometric solid that resembles an ellipse.

Word History and Origins

Origin of -oid¹

< Greek -oeidēs, equivalent to -o- -o- + -eidēs having the form of, derivative of eîdos form

Word History and Origins

Origin of -oid¹

from Greek -oeidēs resembling, form of, from eidos form

Example Sentences

Erasistratos de kantautha proteron poisas to deuteron ouk oid' hops ouk aisthanetai.

From Project Gutenberg

Kaitoi taut' ouk oid' hops exnechthn eipein ou proelomenos all' hyp' auts tou logou ts akolouthias anankastheis.

From Project Gutenberg

Thallog′enous, belonging to the thallogens; Thall′oid, Thall′ose, resembling a thallus.

From Project Gutenberg

Varicell′ar, pertaining to varicella; Varicell′oid, resembling varicella.

From Project Gutenberg

Anthropoid, an′throp-oid, adj. in the form of or resembling man.

From Project Gutenberg

Words That Use -oid

What does -oid mean?

The suffix –oid means “resembling” or “like.” It is often used in scientific terms, especially in biology.

The suffix –oid comes from Greek –oeidēs, from eîdos meaning “form.”

What are variants of –oid?

The plural form of –oid used in the names of zoological classes is –oidea, as in cynoidea. Want to know more? Read our Words That Use article on –oidea.

Examples of -oid

An example of a word you may have encountered that features –oid is
factoid, “an insignificant or trivial fact.” It also refers to something presented as fact but is not necessarily true.

The fact– part of the word here literally means “fact,” as in “something that actually exists.” The suffix –oid means “resembling,” as we have seen. Factoid literally means “resembling a fact.”

What are some words that use the suffix –oid?

• benzenoid
• conoid (using the equivalent form of –oid in Greek)
• erythroid
• haploid
• osteoid

What are some other forms that –oid may be commonly confused with?

• -ode
• -oic

Break it down!

The combining form oste– means “bone.” With this in mind, what does osteoid literally mean?