-itis Definition

ītis, ītəs

suffix

Inflammation or disease of.

Laryngitis.

American Heritage

Excessive preoccupation with, indulgence in, reliance on, or possession of the qualities of.

Televisionitis.

American Heritage

affix

Inflammatory disease or inflammation of (a specified part or organ)

Neuritis, bronchitis.

Webster's New World

Addiction to, or weariness resulting from preoccupation with.

Golfitis.

Webster's New World

noun

(informal) A medical condition accompanied by inflammation.

Wiktionary

(informal, Caribbean) The feeling of sleepiness after eating a heavy meal, usually the itis.

Wiktionary

Other Word Forms of -itis

Singular:

-itis

Plural:

itises

From suffix -itis (“disease characterized by inflammation”). Compare phobia, from -phobia, sophy, from -sophy, ism, from -ism, and ana, from -ana.

From Wiktionary
ModL < L < Gr -itis, orig. fem. of adjectives ending in -itēs, used to modify nosos, disease (later understood, but omitted)

From Webster's New World College Dictionary, 5th Edition
Greek -ītis from feminine of -ītēs adj. suff. (originally modifying feminine noun nosos disease)

From American Heritage Dictionary of the English Language, 5th Edition