Close, like a freezer bag (4)
I believe the answer is:
seal
(Other definitions for seal that I've seen before include "Make airtight" , "stop leaks" , "Sea mammal in sale" , "Insignia for sale" , "Secure; aquatic animal" .)
I believe the answer is:
seal
(Other definitions for seal that I've seen before include "Make airtight" , "stop leaks" , "Sea mammal in sale" , "Insignia for sale" , "Secure; aquatic animal" .)