dissociated type of carboxylic acid (COO-), and also in ester (R-O-R).
We get confused with acid because the suffix of acid is -ate.
I found that even Google translate has a hard time to differentiate. Last time I was reading an article regarding to 3-methylbutyl pentanoate, 3-methylbutyl 3-methylbutyrate, 3-methylbutyl 2-methylbutyrate, butyl pentanoate and propyl hexanoate. When I checked these five compounds in Google translate, it translated them as acid or ester. Fortunately, they are referred as esters in that article.
Those compounds are the five esters that can be detected in dead and decomposed human cadavers.
However, -oate is not the worst one. The worst chemical suffix is -ane!
E. Cuypers et. al., 2015. The Search for a Volatile Human Specific Marker in the Decomposition Process. PLOS One. DOI: 10.1371/journal.pone.0137341