• (n.) A minute soft filamentary process springing from the surface of certain hydroids and sponges.
Pal'po·cil noun [ See Palpus , and Cilium .] (Zoology) A minute soft filamentary process springing from the surface of certain hydroids and sponges. 
palpocil 1. In some hydroids (freshwater coelenterates or invertebrates; such as, jellyfish), a filamentous tactile (touching) process. 2. A minute soft filamentary process springing from the surface of certain hydroids and sponges.