Helios, the sun; helioscope, heliotype.
Hemi, half; hemisphere.
Hieros, sacred; hierarchy, hieroglyphic.
Hippos, a horse; hippopotamus, hippodrome.
Hŏdos, a way; method, period, exodus.
Hŏmos, the same; homœopathy, homogeneous.
Hudor, water; hydraulic, hydrophobia.
Ichthus, a fish; ichthyology.
Idios, one’s own; idiom, idiot, idiosyncrasy.
Isos, equal; isochronous, isobaric (of equal weight).