Medical Definition of mistletoe
: any of various parasitic or semiparasitic plants (family Loranthaceae, the mistletoe family) that have thick leathery mostly opposite and sometimes scaly leaves and include some formerly used in preparations with oxytocic, antispasmodic, or heart-stimulating properties: asa: a European semiparasitic green shrub (Viscum album) having somewhat poisonous leaves, stems, and waxy-white glutinous berries that have been used in folk medicineb: any of various American plants (genus Phoradendron and especially P. serotinum synonym P. flavescens) resembling the true mistletoe of Europe
Seen and Heard
What made you want to look up mistletoe? Please tell us where you read or heard it (including the quote, if possible).