Answer: reseals

AnswerCrossword Clue
RESEALS

Makes airtight again

RESEALS

Tapes shut again

RESEALS

Closes again, as an envelope

RESEALS
Closes back up
RESEALS
Renders hermetic again
RESEALSFixes the weatherproofing on, say
RESEALSGlues back
RESEALSCloses the envelope again
RESEALSRefastens.
RESEALSCloses tight again.
RESEALSFastens again
RESEALSPuts the lid back
RESEALSCloses again
RESEALSFastens anew
RESEALSCaulks the cracks again
RESEALSUses again, as Tupperware
RESEALSCloses tightly again
RESEALSCloses up again
RESEALSCaulks again, e.g.
RESEALSCloses an envelope again, e.g.
RESEALSCloses an envelope anew
RESEALSPuts the top back on, perhaps