1 If the invitation says black tie, women should wear a floor-length, evening gown. 2  A tuxedo is mandatory if you're a man. 3  This is your chance to dress as if you were headed to the Oscars. 4  Black tie optional means that wearing a tuxedo or long evening gown is not mandatory, but guests should feel free to do so.
Ether is an organic functional group consisting of a disubstituted oxygen, or an oxygen atom bonded to 2 carbon atoms (if adjacent to a ketone, functional group is then called an ester).
Define ether. ether synonyms, ether pronunciation, ether translation, English dictionary definition of ether. n. 1. Any of a class of organic compounds in which two hydrocarbon groups are linked by an oxygen atom. 2. A volatile, highly flammable liquid, C4H10O,...