anion vs ion

anion and ion both are nouns.

Word	Noun	Adjective	Verb	Adverb
anion	Yes	No	No	No
ion	Yes	No	No	No

As nouns, ion is a hypernym of anion; that is, ion is a word with a broader meaning than anion:

anion: a negatively charged ion
ion: a particle that is electrically charged (positive or negative); an atom or molecule or group that has lost or gained one or more electrons

anion (noun)	ion (noun)
a negatively charged ion	a particle that is electrically charged (positive or negative); an atom or molecule or group that has lost or gained one or more electrons