halogen

[hal-uh-juh n, -jen, hey-luh-] /ˈhæl ə dʒən, -ˌdʒɛn, ˈheɪ lə-/

noun, Chemistry

any of the electronegative elements, fluorine, chlorine, iodine, bromine, and astatine, that form binary salts by direct union with metals.

Origin

1835-45; halo- + -gen

Related forms

halogenous

[ha-loj-uh-nuh s] /hæˈlɒdʒ ə nəs/ (Show IPA), adjective

Examples from the web for halogen

No visible shadows, not with them new halogen overheads.
Methane is violently reactive with oxidizers, halogens, and some halogen-containing compounds.
On one side of the cylindrical chamber, about halfway down its length, is a halogen movie-projector lamp.
For each cook who swears by halogen cooktops, another swears at them.
Other energy-efficient lighting options include halogen incandescent bulbs and compact fluorescent lamps.
The wiring loom uses recycled and halogen-free materials instead of polyvinyl, a move intended to make it more easily recycled.
When you flick the switch, the halogen bulb lights instantly.
When you switch it on, the box shines a halogen light on the cup and casts a colorful shadow onto the wall.
That's the equivalent light that comes from a standard halogen lamp, at a fraction of the power.
The light, falling from rows of halogen lamps in the ceiling high overhead, is even and brilliant.

British Dictionary definitions for halogen

halogen

/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, adjective
halogenous (həˈlɒdʒɪnəs) adjective

Word Origin

C19: from Swedish; see halo-, -gen

Word Origin and History for halogen

general name for elements of the chlorine family, 1842, from Swedish, coined by Swedish chemist Baron Jöns Jakob Berzelius (1779-1848), literally "salt-producer," from Greek hals "salt" (see halo-) + -gen "giving birth to" (see -gen); so called because a salt is formed in reactions involving these four elements.

halogen in Medicine

halogen hal·o·gen (hāl'ə-jən)
n.
Any of a group of five chemically related nonmetallic elements including fluorine, chlorine, bromine, iodine, and astatine.

halogen in Science

halogen

(hāl'ə-jən)
Any of a group of five nonmetallic elements with similar properties. The halogens are fluorine, chlorine, bromine, iodine, and astatine. Because they are missing an electron from their outermost shell, they react readily with most metals to form salts. See Periodic Table.