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).
Ether is the name of the currency used within Ethereum. It is used to pay for computation within the EVM. This is done indirectly by purchasing gas for ether as explained in gas. Ethereum has a metric system of denominations used as units of Ether. Each denomination has its own unique name (some bear the family name of seminal figures playing a role in evolution of computer science and cryptoeconomics). The smallest denomination aka base unit of Ether is called Wei.