The Collaborative International Dictionary
Viscin
Viscin \Vis"cin\, n. (Chem.) A clear, viscous, tasteless substance extracted from the mucilaginous sap of the mistletoe ( Viscum album), holly, etc., and constituting an essential ingredient of birdlime.
Wiktionary
viscin
n. A material extracted from the mucilaginous sap of the mistletoe and used to make birdlime.