1) In an airtight manner 
• (adv.) In an hermetical manner; chemically. • (adv.) By fusion, so as to form an air-tight closure.
Her·met'ic·al·ly adverb 1. In an hermetical manner; chemically. Boyle. 2. By fusion, so as to form an air-tight closure. » A vessel or tube is hermetically sealed when it is closed completely against the passage of air or other fluid by fusing the extremity; --...
[adv] - in an airtight manner
hermetical, hermetically 1. Made perfectly close or air-tight by fusion, so that no gas or spirit can enter or escape; as, an hermetic seal. 2. Of or pertaining to the system which explains the causes of diseases and the operations of medicine on the principles of the hermetic philosophy, and which made much use, as a remedy, of an alkali and an a...
adverb in an airtight manner; `this bag is hermetically sealed`