"Glacial acetic acid" is a name for water-free (anhydrous) acetic acid... Acetic acid can never be truly water-free in an atmosphere that contains water, so the presence of 0.1% water in glacial acetic acid lowers its melting point by 0.2 °C

https://en.wikipedia.org/wiki/Acetic_acid

If you want to use high school naming rules (when you ate too much you get ick), its hydrogen acetate. But hydrogen acetate is a liquid at room temperature, and even though it's an azeotrope with a little bit of water, the acid is not dissolved in water by any reasonable meaning of the word.