caulking (Noun) — A waterproof filler and sealant that is used in building and repair to make watertight.
caulking (Verb) — Seal with caulking. ex. "caulk the window"
caulking (Verb) — (animal husbandry) provide with calks. ex. "caulk horse shoes"
caulking (Verb) — Injure with a calk.