酐 is a chemistry term, short for 酸酐 (acid anhydride) — the oxide left when an acid loses water. The wine-jar radical marks it as part of the chemical-substance character family.
Left is 酉, a picture of a wine jar. As a radical it groups characters about fermented and chemical substances — 酸 (acid), 酒 (alcohol) — and so suits this chemistry word.
