Main Entry:

an·ion

Pronunciation:

\ˈa-ˌnī-ən\

Function:

noun

Etymology:

Greek, neuter of aniōn, present participle of anienai to go up, from ana- + ienai to go — more at issue

Date:

1834

: the ion in an electrolyzed solution that migrates to the anode ; broadly : a negatively charged ion