Mistletoe

Well, here’s a bit of a surprise. The word mistletoe may be related to the Proto-Indo-European (PIE) root meigh (to urinate)! The origins of the word mistletoe are unknown; however, one suggestion is that the mistletoe plant is propagated through the droppings of the missel thrush or missel-bird. These droppings are called mih-stu- (urine), a Germanic term from PIE meigh.
 
The word mistletoe is first seen in the Proto-Germanic mikhstilaz (mistletoe) and Old English mistel (basil, mistletoe) and mistiltan (mistle twig). Mistletoe is a European plant which grows parasitically on certain trees.
 
Mistletoe was venerated by the Druids of ancient Britain. The white berries were considered symbols of male fertility (i.e., semen). The ancient Romans hung mistletoe over doorways as a symbol of peace, love, and understanding as well as for protection of the household. Mistletoe was part of the Roman Saturnalia celebrations. Christian Christmas celebrations continued this tradition. The custom of kissing under the Christmas mistletoe appears to have originated in the late 18th or early 19th centuries among the servants of English country houses.
 
Reference: Online Etymological Dictionary, https://www.etymonline.com/