(click for larger image in new window) n.
pl.per·i·he·li·a (-hē'lē-ə, -hēl'yə) The point nearest the sun in the orbit of a planet or other celestial body.
[Alteration of New Latin perihēlium : peri- + Greek hēlios, sun; see sāwel- in Indo-European roots.] per'i·he'li·al (-hē'lē-əl, -hēl'yəl) adj.
"point at which a celestial body is nearest the Sun," 1690, coined in Mod.L. (perihelium) by Kepler (1596) from Gk. peri "near" + helios "sun" (see sol), and subsequently re-Grecianized.