A halogen is one of a group of chemical elements that includes chlorine, fluorine, and iodine.Halogens are often used in lighting and heating devices.
...a halogen lamp.
halogen in British English
(ˈhæləˌdʒɛn)
noun
any of the chemical elements fluorine, chlorine, bromine, iodine, and astatine. They are all monovalent and readily form negative ions
Derived forms
halogenoid (ˈhalogenˌoid)
adjective
halogenous (həˈlɒdʒɪnəs)
adjective
Word origin
C19: from Swedish; see halo-, -gen
halogen in American English
(ˈhælədʒən)
noun
any of the five very reactive, nonmetallic chemical elements making up group VIIA of the periodic table: fluorine is the smallest and most reactive of the group, and astatine is the largestand least reactive
Derived forms
halogenous (haˈlogenous) (hæˈlɑdʒənəs)
adjective
Word origin
halo- + -gen
Examples of 'halogen' in a sentence
halogen
Here are the Byzantine colours of the city's mosaic; here are saints ' haloes glowing around the halogen bulbs.
Sean Thomas THE CHEEK PERFORATION DANCE (2002)
The clearing had become a dome of light, a circle watched over by the ferocity of a dozen halogen lamps.
Robert Wilson BLOOD IS DIRT (2002)
Beneath blue halogen lamps, I saw huge metal tubs ten feet high, and fat ceramic insulators thick as a man's leg.