|n. pl.||1.||(Zool.) A division of annelids including those which construct, and habitually live in, tubes. The head or anterior segments usually bear gills and cirri. Called also Sedentaria, and Capitibranchiata. See Serpula, and Sabella.|
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.