propolis

PRO'POLIS, n. [Gr. before the city, or the front of the city.]

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 air, &c. Pliny represents it as the third coat; the first he calls commosis; the second pissoceros; the third, more solid than the others, he calls propolis.