From Longman Dictionary of Contemporary Englishmistletoemis‧tle‧toe /ˈmɪsəltəʊ $ -toʊ/ noun [uncountable] HBPa plant with small white berries, which grows on trees. It is traditional to kiss people under a piece of mistletoe at Christmas.
Examples from the Corpus
mistletoe• There was a mistletoe branch hanging above the bed.• Today saw the first of four weekly auctions, and five tons of holly and mistletoe were brought in by local farmers.• Are we delicate mistletoe, paying lip service to the green theme, or full-blown Lincoln green?• From Tenbury Wells market, mistletoe is sold on to other markets all over Britain.• However, it was not total since, oddly, mistletoe would be the death of him.• Using a long hooked pole, he yanked down the mistletoe from the boughs of an old apple tree.• Where's the mistletoe and some one to kiss?• The reddening turned the mistletoe into rowan.Origin mistletoe Old English misteltan, from mistel “mistletoe” + tan “small stem” 