ambrosiate adjective 1noun 1forms 2 adjective1 •Ambrosial. noun1 •A crystalline substance, C₂₃H₂₅O₅Br, that is one of the common irritants that can be refined from ragweed (Ambrosia artemisiifolia).The absolute configuration of ambrosic acid a crystallographic study of p-bromophenacyl ambrosiate. — 1974 formsmore ambrosiate · most ambrosiate