anionic

WordReference Random House Unabridged Dictionary of American English © 2026

an•i•on  (an′ī′ən), n. [Physical Chem.]

1. Chemistry a negatively charged ion, as one attracted to the anode in electrolysis.
2. Chemistry any negatively charged atom or group of atoms (opposed to cation).

• Greek, neuter of anió̄n going up (present participle of aniénai to go up), equivalent. to an- an-³ + -i- go + -ōn present participle suffix
• 1825–35;

an•i•on•ic  (an′ī on′ik), adj.  an′i•on′i•cal•ly, adv.