Rotating image of human brain, illustrating the lateral sulcus in the brain. The term sulcus (pl. sulci) is a general descriptive term for a furrow or fissure.
Halo may refer to: 1  Halo (religious iconography), a glow or ring of light around a head or person in art. 2  Halo (series), video game franchise.
Freebase (0.00 / 0 votes) Rate this definition: Halogen. The halogens or halogen elements are a group in the periodic table consisting of five chemically related elements, fluorine, chlorine, bromine, iodine, and astatine. The artificially created element 117 may also be a halogen. In the modern IUPAC nomenclature, this group is known as group 17.