Greek and Latin roots in English

Root	Meaning in English	Origin language	Etymology (root origin)	English examples
ichthy-	fish	Greek	ἰχθύς (ichthus)	ichthyology
icos-	twenty	Greek	εἴκοσι (eikosi)	icosagon, icosahedron
id-	shape	Greek	εἶδος (eidos)	idol
ide-	idea; thought	Greek	ιδέα (idea)	ideogram, ideology
idio-	peculiarity	Greek	ἴδιος (idios) "private, personal, one's own"	idiom, idiosyncrasy, idiosyncratic, idiot
ign-	fire	Latin	ignis	igneous, ignite, ignition
imagin-	copy	Latin	imāgō, imāginis	image, imagine
in- (1), il-, im-	in, on	Latin	in	illuminate, import, incur, intend, invite
in- (2), il-, im-, ir-	not, un- (negation)	Latin	in-	illicit, impossible, inimical, irrational
infra-	below, under	Latin	infra	infrastructure
insul-	island	Latin	insula	insular, insulation
inter-	among, between	Latin	inter (preposition)	intercollegiate, intermission, intersection
intra-	within	Latin	intra	intramural
irasc-, irat-	be angry	Latin	irasci	irascible, irate
irid-	rainbow	Latin	iris	iridescent
is-, iso-	equal, same	Greek	ἴσος (isos)	isometric, isomorphic, isotonic, isotropic
iter-	again	Latin	iterum, iterare	iteration
itiner-	journey	Latin	iter, itineris	itinerary

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