a combining form meaning “sun,” used in the formation of compound words: heliolatry.
Also especially before a vowel, heli-.

Origin of helio-

< Greek, combining form of hḗlios sun
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British Dictionary definitions for helio-


before a vowel heli-

combining form

indicating the sunheliocentric; heliolithic

Word Origin for helio-

from Greek, from hēlios sun
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