Holly is not related to holy, though hollyhock is indeed an alteration of holyhock (what made the hock “(marsh)mallow” holy is anybody’s guess, especially because the origin of hock, a plant name, is unknown, but the oft-repeated conjecture that the hollyhock was brought from the Holy Land has no foundation in the word’s history). Its connection with Christmas depends on its being an evergreen and thus serving as a symbol of fertility, or, if a more flamboyant phrase is needed, of life everlasting. This is why two effigies—of a holly boy and an ivy girl—“figured in certain village sports in East Kent on Shrove Tuesday” (OED). The Old English for holly was holen or holegn (the latter being pronounced as holeyn). The Germans of that time called the plant huls (Modern German Hulst, Modern Dutch hulst). The Celts also had a cognate of holly from early on, but the French borrowed the Germanic word (Modern French houx: both consonants are mute in it). In the remote days of the Proto-Indo-Europeans, holly (at that time its root—the word’s, not the plant’s—was presumably kel-) meant “prickly.” At the end of Act II of As You Like It, we hear jubilant chorus: “Heigh-ho! sing, heigh-ho! unto the green holly.” Today we are more apt to sing heigh-ho “unto” Hollywood, but such is life, and no one is allowed to take a holiday from history.
Since the mistletoe is also an evergreen, its cult in religious beliefs (it was held in peculiar veneration by the Druids) and kissing under it at Christmas do not come as a surprise (however, the kissing, immortalized in Pickwick Papers, appears to be a recent custom). Only the Scandinavian myth is unnatural, for in it the mistletoe, instead of promising the eternal return of life, kills the protagonist, but before turning to this development, let us look at the word. The element -toe meant “twig” and originally ended in -n (Old Engl. misteltan), which was probably taken for a marker of the plural and therefore shed. Mistel- may be connected with the Germanic word for “dung” (Modern German Mist has retained that meaning; the relatedness of Engl. mist to its German homonym needs some elaboration). The mistletoe is said to be disseminated by birds; allegedly, they eat the berries and disperse the undigested seeds in their droppings. If mist in mistel indeed refers to the plant’s life cycle, then -el is an obscure suffix. The Latin for mistletoe is viscum. From viscum we have the adjective viscous, and, since birdlime is made from the glutinous substance found in the berries of the mistletoe (or from the inner bark of the holly!), the Latin noun meant both “mistletoe” and “birdlime.” Hence the cynical Latin proverb “the thrush defecates its own destruction” (turdus sibi malum cacat). According to another suggestion, mistel is an ignorant alteration of viscum, but the old etymology seems to be more trustworthy. The mistletoe (Viscum album) is a pendent parasite shrub (a small bush) growing on various trees. It kills its host, but this circumstance should not give us wrong ideas about the Scandinavian myth.
Two medieval Icelandic books tell that the shining and beloved god Baldr began to have bad dreams. His mother Frigg exacted an oath from fire, water, and all animate and inanimate objects that they would not harm Baldr. Only the mistletoe seemed to be too young to her (a most implausible explanation) and was not asked to swear an oath of allegiance. The gods’ favorite pastime consisted in meeting at the assembly and throwing stones or shooting at Baldr. Baldr remained unhurt. His invulnerability irritated Loki, a god notorious for evils tricks. He disguised himself as a woman and went to Frigg’s distant abode. There he learned that the mistletoe had not been part of the conspiracy to spare Baldr. He returned to the assembly, tore the mistletoe off or up and talked Hodr, a blind god, into hurling it at Baldr. The bush turned into an arrow or spear and pierced Baldr. The god fell dead.
This myth has made the word mistletoe known all over Scandinavia. Every detail in the story is puzzling and has been discussed innumerable times, but we will only ask why the mistletoe was chosen for the role of the fatal weapon. This plant does not grow in Iceland and is known in a very limited area of Norway. Therefore, neither the medieval Icelanders nor the Norwegians in the regions from which most Icelanders stemmed had seen it. If they had been familiar with the mistletoe, they would have known that no magic would be able to turn the crooked bush into an arrow or a spear. Even the word mistilteinn (the Icelandic for mistletoe) was probably borrowed from Old English. In its Icelandic guise, it occurred only in the Baldr myth; the popular Scandinavian names of the plant were and still are different.
Most likely, Baldr was at one time venerated as a fertility god residing in the sky (by contrast, the blind Hodr must have been his subterranean enemy), and a certain plant was sacred to him, as in Greek mythology the myrtle was sacred to Aphrodite. This is why Frigg passed it over in the ceremony of swearing: the mistletoe was loyal to Baldr by definition and did not have to prove its loyalty. But, according to another widespread belief, a great warrior or supernatural being could be killed only with its own weapon. Thus the one object in the world inseparable from Baldr and faithful to him was destined to become an instrument of his destruction. Such is the bitter contradiction of mythic thinking. We have no way of finding out what that plant was. In the myth it was at some time replaced with the mistletoe, perhaps because the word mistilteinn, which reached Norway during the Viking raids, had an ominous ring to a medieval Scandinavian: mist- was associated with death, and -teinn occurred as the second element in sword names. The terrible borrowed word, which had an innocuous meaning in Old English, emerged in its new home as “sword of death” and ousted the reed or the thistle, or whatever plant was familiar to the Scandinavians as a magical tool of slaying people. Baldr’s doom was to be killed (no other tale of him has come down to us), but the weapon that hurt him in the latest redaction of the myth seems to owe its existence to the vagaries of Icelandic semantics. Be careful when you play with words! If you misunderstand them, they will retaliate. But the mistletoe should be exonerated. It kills its host, but it poses no danger to gods or humans. As to kissing under it, the joy one gets from this procedure is a matter of taste.
Anatoly Liberman is the author of Word Origins…And How We Know Them. His column on word origins, The Oxford Etymologist, appears here each Wednesday. Send your etymology question to firstname.lastname@example.org; he’ll do his best to avoid responding with “origin unknown.”