propolis

A thick odorous substance having some resemblance to wax and smelling like storax; used by bees to stop the holes and crevices in their hives to prevent the entrance of cold airPliny represents it as the third coat; the first he calls commosis; the second pissoceros; the third, more solid than the others, he calls propolis. This account of the propolis may not be perfectly correct, as authors do not agree in their descriptions of it.