Other forms: caulking, caulked, caulks
To caulk is to seal the join around a bath or window. Caulk the gap, silicone caulk, recaulk the bath.
The trick is a steady bead and a wet finger to smooth it, and the surface must be dry or it will not stick. The word is nautical: caulking a wooden ship meant driving fibre into the seams and sealing them with pitch, without which the hull leaked. Note that the Latin means to fill with lime.
1verbcaulkTo seal a join with a waterproof filler.
“Caulk the gap around the bath so water can't leak through.”
caulk is a sealing.
Old French cauquer comes from Latin calicare, to fill with lime, from calx. Chalk and calcium come from the same lime.
Latin
calicāre — to fill in with limestone, caulk
fro-nor
cauquer
English, today
caulk
Built from
From fro-nor cauquer, from Latin calicāre (“to fill in with limestone, caulk”), derived from calx (“limestone, chalk”). Related to a doublet of calx and cauk and chalk and calculus.
Etymology from Wiktionary, CC BY-SA