What does "maleate" mean?

Any salt or ester of maleic acid.

Maleate

Common synonyms include: carboxylate ion, conjugate base, dianion, diester, ester of maleic acid, maleate ion.

noun

noun ·Rare ·Advanced level

Noun

1
Any salt or ester of maleic acid.
2
a salt or ester of maleic acid; used as a nontricyclic antidepressant drug for psychomotor activation wordnet

From maleic acid + -ate (“salt or ester”).