SIPHON, ALSO SYPHON

(1) A pipe or tube fashioned or deployed in an inverted U shape and filled until atmospheric pressure is sufficient to force a liquid from a reservoir in one end of the tube over a barrier higher than the reservoir and out the other end. (2) (Zoology) A tubular organ, especially of aquatic invertebrates such as squids or clams, by which water is taken in or expelled.