plural suffix sometimes preserved in English for words from Latin, it is the Latin plural of nouns of the second declension (such as focus/foci, radius/radii).

as a termination in certain people names (Iraqi, Israeli), it represents the common Semitic national designation suffix -i.

word-forming element in names of countries, diseases, and flowers, from Latin and Greek -ia, noun ending, in Greek especially used in forming abstract nouns (typically of feminine gender); see -a (1). The classical suffix in its usual evolution (via French -ie) comes to Modern English as -y (as in familia/family, also -logy, -graphy). Compare -cy.

In paraphernalia, Mammalia, regalia, etc. it represents Latin or Greek -a (see -a (2)), plural suffix of nouns in -ium (Latin) or -ion (Greek), with formative or euphonic -i-.

adjectival word-forming element, variant of -al (1) with connective -i-. From Latin -ialis, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective.

variant of suffix -an (q.v.), with connective -i-. From Latin -ianus, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective. In Middle English frequently it was -ien, via French.

form of -ana (q.v.) with nouns whose adjectival forms end in -ian.

medical Latin word-forming element used in naming diseases, from Greek -asis, abstract noun suffix (often expressing "disease, morbid condition") from the aorist of verbs in -aein. The -i- is connective.

word-forming element meaning "medical treatment," from French -iatrie, from Greek iatreia "healing, medical treatment" (see -iatric).

word-forming element, from Latinized form of Greek iatrikos "healing," from iatros "physician, healer" (related to iatreun "treat medically," and iasthai "heal, treat"); of uncertain origin, perhaps from iaomai "to cure," related to iaino "heat, warm, cheer," probably from a root meaning "enliven, animate."

word-forming element making adjectives from verbs, borrowed in Middle English from Old French -ible and directly from Latin adjective suffix -ibilis (properly -bilis); see -able.