ichidan verb, transitive verb
seal up; enclose by coating
To completely cover and seal something by applying a thick layer of paint, plaster, or similar substance, often trapping it inside.
壁の穴をセメントで塗り込める。
Seal up the hole in the wall with cement.
彼は手紙を壁の中に塗り込めた。
He sealed the letter inside the wall by plastering over it.