What describes an enclosure that is airtight and impervious to external influence?

The term that best describes an enclosure that is airtight and impervious to external influence is "hermetically sealed." This phrase originates from the name of the ancient Greek god Hermes, who was associated with protection and secrecy. In contemporary usage, a hermetically sealed environment refers to a space that has been completely sealed off from air and moisture, preventing the exchange of gases and other external factors.

This characteristic makes "hermetically sealed" the most accurate choice because it explicitly conveys the notion of airtightness and the ability to prevent any external influences or contamination. In various applications, such as in food preservation or laboratory settings, items are often placed in hermetically sealed containers to maintain their integrity and prevent spoilage or reactions with outside elements.

The other options, while they may describe types of enclosures or containers, do not capture the comprehensive definition of being both airtight and completely safeguarded from external factors in the same way. For example, a sealed coffin could be airtight but does not imply the same level of imperviousness, and a ground vault might be protected from external elements but not necessarily sealed from air. Waterproof denotes protection against water but does not address air exchange or broader external influences. Thus, "hermetically sealed" is