|bī, (ˈ)bī+ noun
Etymology: International Scientific Vocabulary bi- (I) + acetyl
: a greenish yellow liquid diketone (CH 3 CO) 2 , with an odor like that of quinone that is found in some essential oils (as bay oil), that is chiefly responsible for the flavor of butter and also contributes to the aroma of coffee and tobacco, and that is made synthetically and used as a flavoring agent in foods (as margarine); 2,3-butane-dione — called also diacetyl