hal·o·gen
noun/ˈhælədʒən/
/ˈhælədʒən/
(chemistry)- any of a set of five chemical elements, including fluorine, chlorine and iodine, that react with hydrogen to form acids from which simple salts can be made. Halogens, in the form of gas, are used in lamps and cookers.
卤素 Oxford Collocations DictionaryHalogen is used before these nouns:- bulb
- lamp
- light
- …
Word Originmid 19th cent.: from Greek hals, halo- ‘salt’ + -gen.