1680s, from helio- + -centric.

1848, "instrument for taking photographs of the sun," from helio- "sun" + -graph "something written." Earlier, "a description of the sun" (1706, implied in heliographic). From 1877 as the name of a movable mirror used in signaling. Related: Heliographical.

Heliography (1845) was the word for the product of a type of engraving process by chemical reaction from exposure to sunlight. It also was an early term for what came to be called photography (1840).

1817, from helio- "sun" + -latry "worship of." Related: Heliolater (1828).

1865, from helio- "sun" + -phobia "fear." Perhaps directly from German (where it was in use 1850s). Related: Heliophobe (1885); heliophobic (1886).

*sāwel-, Proto-Indo-European root meaning "the sun." According to Watkins, the *-el- in it originally was a suffix, and there was an alternative form *s(u)wen-, with suffix *-en-, hence the two forms represented by Latin sol, English sun.

It might form all or part of: anthelion; aphelion; girasole; heliacal; helio-; heliotrope; helium; insolate; insolation; parasol; parhelion; perihelion; Sol; solar; solarium; solstice; south; southern; sun; Sunday.

It might also be the source of: Sanskrit suryah, Avestan hvar "sun, light, heavens;" Greek hēlios; Latin sol "the sun, sunlight;" Lithuanian saulė, Old Church Slavonic slunice; Gothic sauil, Old English sol "sun;" Old English swegl "sky, heavens, the sun;" Welsh haul, Old Cornish heuul, Breton heol "sun;" Old Irish suil "eye;" Avestan xueng "sun;" Old Irish fur-sunnud "lighting up;" Old English sunne German Sonne, Gothic sunno "the sun."