Hermetic/hɜːrˈmetɪk/ Definition 1 of 3Pro Tip 1/3Absolute Seal The term emphasizes an absolute seal, without any leaks. The laboratory containers were hermetic to prevent contamination. Pro Tip 2/3Preservation Quality Hermetic sealing is key for long-term storage of food or materials. Food companies use hermetic packaging to extend shelf life. Pro Tip 3/3Technical Context It is often used in technical contexts like engineering or science. The spacecraft's compartments must be hermetic to protect the crew.