phosphonium

[ fos-foh-nee-uh m ]
/ fɒsˈfoʊ ni əm /

noun Chemistry.

the positively charged group PH4+.

Origin of phosphonium

First recorded in 1865–70; phosph(orus) + (amm)onium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019