To cover something up with paint so as to hide or obscure it. A noun or pronoun can be used between "paint" and "out." Staff were quick to paint over the obscene graffiti on the side of the gymnasium. Someone came by and painted certain words over that were featured on the mural on Main Street.
paint over something
to cover something up with a layer of paint. Sam painted over the rusty part of the fence. The work crew was told to paint over the graffiti.