Plug tightly (4)
I believe the answer is:
seal
(Other definitions for seal that I've seen before include "Close - (performing?) animal" , "Mammal; impressed wax" , "relative of the walrus" , "Stick down" , "A mammal; a fastening" .)
I believe the answer is:
seal
(Other definitions for seal that I've seen before include "Close - (performing?) animal" , "Mammal; impressed wax" , "relative of the walrus" , "Stick down" , "A mammal; a fastening" .)