The alchemists, as the people were called who tried to make gold, considered themselves followers of Hermes, and often called themselves Hermetic philosophers. A. B. Buckley. [ 1913 Webster ]
Hermetic art,
Hermetic books.
adv.
☞ A vessel or tube is hermetically sealed when it is closed completely against the passage of air or other fluid by fusing the extremity; -- sometimes less properly applied to any air-tight closure. [ 1913 Webster ]