olemus
Wiktionary:
7. something designed to prevent liquids or gases from leaking through a joint

näiteid
https://duckduckgo.com/?q=elastic+seal&t=h_&iar=images&iax=images&ia=images

https://duckduckgo.com/?q=hermetic+seal&t=h_&iar=images&iax=images&ia=images

ülevaateid
https://en.wikipedia.org/wiki/Seal_(mechanical)