caulk

English Thesaurus

1. a waterproof filler and sealant that is used in building and repair to make watertight (noun.substance)

hypernym	:	sealant, sealer,
definition	:	a kind of sealing material that is used to form a hard coating on a porous surface (as a coat of paint or varnish used to size a surface) (noun.substance)

2. seal with caulking (verb.contact)

hypernym	:	seal, seal off,
definition	:	make tight; secure against leakage (verb.contact)