Definition of halogen
(Entry 1 of 2)
: any of the five elements fluorine, chlorine, bromine, iodine, and astatine that form part of group VIIA of the periodic table and exist in the free state normally as diatomic molecules
halogen
adjectiveDefinition of halogen (Entry 2 of 2)
: containing, using, or being a halogen
a halogen lamp
Buying Guide
Our Reviews team has selected the best flashlights.
Test Your Vocabulary
Commonly Confused Words Quiz
-
- I went to the ______ store to buy a birthday card.

Test your knowledge - and maybe learn something along the way.
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Share halogen
Time Traveler for halogen
The first known use of halogen was in 1842
See more words from the same year