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a noun suffix occurring in loanwords from Greek: psoriasis.
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Which sentence is correct?
Compare -asis.

Origin of -iasis

<Greek, equivalent to -iā- v. formative + -sis-sis

Words nearby -iasis

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does -iasis mean?

The form -iasis is a suffix used to denote the names of disease or other nouns of state or process. It is often used in medical terms, especially in pathology.

The form -iasis comes from Greek -íasis, denoting the names of diseases. It is a common misconception that -íasis comes from the verb iâsthai, meaning “to heal,” which is the source of the combining forms -iatry and iatro-. Instead, -iasis is derived from the Greek verb ending -áein (also ân), with the initial –i– used as a connecting vowel, featuring the noun-forming suffix -sis.

Examples of -iasis

One example of a word you may have come across that uses the form -iasis is psoriasis, “a common chronic, inflammatory skin disease characterized by scaly patches.” Psoriasis comes from Greek psōríāsis, which uses the equivalent form of -iasis in that language.

The psor- part of the word comes from Greek psṓra, meaning “itch.” The suffix -iasis roughly translates to “itchy disease.”

What are some words that use the combining form -iasis?

What are some other forms that -iasis may be commonly confused with?

Break it down!

The combining form lith- means “stone.” With this in mind, what is the literal translation of lithiasis?

British Dictionary definitions for -iasis



n combining form
(in medicine) indicating a diseased conditionpsoriasis Compare -osis (def. 2)

Word Origin for -iasis

from New Latin, from Greek, suffix of action
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012