Meaning

noun a tube running from the liquid in a vessel to a lower level outside the vessel so that atmospheric pressure forces the liquid through the tube

noun a tubular organ in an aquatic animal (especially in mollusks) through which water can be taken in or expelled

verb convey, draw off, or empty by or as if by a siphon

originFrom Middle French siphon, from Old French sifon, from Latin sīphō, from Ancient Greek σίφων (síphōn, “pipe, tube”), of uncertain origin; possibly related to Latin tibia (“pipe, flute of bone”), with the irregular forms suggesting a non-Indo-European loan source, perhaps of the shape *twi-, *twibh.

Etymology from Wiktionary, CC BY-SA 3.0