phosphorous
Pronunciation: /ˈfɒsf(ə)rəs/
adjective
- relating to or containing phosphorus. Compare with phosphoric.
- Chemistry of phosphorus with a valency of three.
- phosphorescent.
The correct spelling for the chemical element is phosphorus, while the adjective meaning ‘relating to or containing phosphorus’ is spelled phosphorous. A common mistake is to use the spelling phosphorous for the noun as well as the adjective.