Olwen. [W] "She of the white track," so named because four white trefoils sprang up wherever she trod. The beautiful daughter of Yspaddaden Pencawr, "chief giant," who lived with her father in a fortress. Culhwch overcomes many difficulties to make her his wife. She has similarities to Etain in Irish myth.

Oonagh. [I] Wife of Fionnbharr, relegated from an ancient goddess of the De Danaan in popular folklore to "queen of all the fairies in Ireland." Oonagh and Fionnbharr dwelt at the sidhe of Meadhna, five miles west of Tuam.

Oral Tradition. It was not until the early Christian period that the Celts began to write extensively in their own languages. For hundreds of years prior to that time, Celtic law, poetry, philosophy, science, history, genealogy, and literature were passed down in oral form. Julius Caesar commented of the Celts: "They commit to memory immense amounts of poetry. And some of them continue their studies for twenty years. They consider it improper to commit their studies to writing." It is clear that this was a religious prohibition rather than an inability to write, for we find that the Celts could and did leave inscriptions on occasion, mainly funerary inscriptions in Greek and Latin characters.  Such Celtic inscriptions have been found in northern Italy and northern Spain. A find in 1983 of a lead tablet written in Latin cursive has provided us with the longest known Gaulish text to date (Etudes celtique, Paris, CNRS, Vol. XXII, )985). Prior to this, the most extensive text in Gaulish was the Coligny calender, dated to the first century B.C., now in the Musee Des Arts, Lyons, France. It is argued that when the Greeks first recorded the name Keltoi as a name for the Celts, they were recording a name by which the Celts referred to themselves-"the secret people." The word ceillt still means "hidden" in modern Irish, and this is also thought to be the etymology of the word "kilt," for obvious reasons. It is accepted that many of the stories of Celtic myth were ancient even at the time when Christianity had replaced the ancient Celtic religion, which had placed such a prohibition on writing. And when the Christian scribes came to write down the stories, such as the Red Branch Cycle, they might have already been passed down orally for a thousand years. In the myths we learn that the Irish literati had a secret literary language, berla na filied (the language of the poets), which only the initiated could understand.

Orc- Triath. [I] See Torc Triath.

Oriel. [I] The Irish form for Airgialla, signifying "subject people." The kingdom of Oriel consisted of the modern countries of Armagh, Monaghan, Tyrone, and most of Fermanagh and Derry.

Orlam. [I] A son of Ailill and Medb slain by Cuchulainn.

Orna. [I] The Sword of Tethra, the Fomorii king, which could speak and recount jits deeds. Having killed Tethra at the second battle of Magh Tuireadh, Ogma claimed the sword.

Oscar. [I] Sonl of Oisin and Eibhir and grandson of Fionn Mac Cumhail and Sadb. The name-Os (deer) and car (lover)-reflects that of his father, whose mother was the goddess Sadb, who had been turned iinto a deer by the Dark Druid. Oscar was the mightiest warrior of thl.e Fianna, a man of hard strength with a heart "like a twisted hornl sheathed in steel." He was given command of a battalion of the Fianna that was called "The Terrible," Broom" because it would not retreat an inch but swept its enemies from the field. He married Aidin. When Cairbre the High King sought to curb the poweer of the Fianna, which Oscar now commanded, Oscar led them in to the battle at Gabhra (Garristown, Co. Dublin). The battle saw the destruction of the Fianna. Oscar, however, killed Cairbre in simgle combat but was himself was mortally wounded. His wife, Aidin. died of grief  Fionn Mac Cumhail returns from the Otherworld too lament him, and his father, Oisin, comes to carry his bier with the hero Celta.

Oshin. Manx equivalent of Oisin, son of Fionn Mac Cumhail.

Ossar. [I] The mound of Mac Da Tho that was coveted by Ailill and Medb and also by Conchobhar Mac Nessa. In another version, the hound is call red Ailbe. At the end of the story of "Mac Da Tho's Boar," the dog chases Ailill's chariot and is killed by his charioteer..

Ossian. Scottish. equivalent of Oisin, son of Fionn Mac Cumhail.

Otherworld.A general term for the various lands of the gods, both good and evil" and for the place where one was reborn after death. The Celts were one of the first European peoples to evolve a doctrine of innmortality of the soul. The basic belief was that death was only a chaanging of place and that life went on with all its forms and foods in another world, a world of the dead that gave up living souls to this world, An exchange of souls was always taking place between the two worlds; death in this world brought a soul to the Otherworld, and death in the Otherworld brought a soul to this world. Because of this, Philostratus of Tyana (ca. A.D. 170-249) i observed that the Celts celebrated birth with mourning and death with joy. They mourned birth because it meant someone had died in the Otherworld and celebrated death because it meant a rebirth in the Otherworld.

It was believed that on one night of the year the Otherworld became visible to mankind. This was the Feast of Samhain (October 31/November 1). On this night all the gates to the Otherworld were opened and the inhabitants could set out to wreak vengeance on, those living in this world who had wronged them. This ancient; belief survived into Christianity as Hallowe'en, the evening of All Hallows, or All Saints' Day on November 1. The modern Christian idea is that it is the night when witches and demons and spirits from Hell set out to ensnare unsuspecting souls.
The forms of Otherworlds range from dark, brooding purgatories of the Fomorii islands to the sunny lands of the Land of Youth or Land of Promise. The Otherworlds of both the Irish and Welsh are similar, and mortal humans could adventure and live in the Otherworld. Pwyll can journey to Annwn, while Cuchulainn can adventure in Hy-Falga. Most of the renditions of the Otherworld are generally as islands to the southwest of Ireland or Wales. The most famous sojourn in the Otherworld was that of Oisin, who rode off on a magical horse with Niamh, the daughter of the sea god Manannan Mac Lir, and stayed there for three hundred years.

Owain. [W] Son of Urien. He is a warrior of Arthur's, and in the tale of "The Dream of Rhonabwy" he plays a chess game with Arthur. When Cymon is defeated by the Black Knight, Owain sets out to find and defeat him. Having done so, he finds the Castle of the Fountain and is rescued from imprisonment by a maiden called Luned, who gives him a ring to make him invisible. She then helps him win the hand of the Lady of the Fountain. After three years Arthur and his companions come looking for him. He returns to Arthur's court and forgets his Lady. She comes after him and calls him a deceiver, a traitor, and faithless. He is ashamed and Bees into a desolate country where he becomes a recluse. Near death, he is restored to strength by the magic of a noble woman and her handmaidens. He has to slay a lion and a serpent. Finally he finds Luned imprisoned and about to face death by burning. He rescues her , defeats a black giant and releases 24 maidens from his imprisonment, and then returns to the Lady of the Fountain. The saga therefore ends happily. One mysterious point of the tale is that Cenferchyn, according to "The Dream ofRhoriabwy," gave Owain 300 ravens, which formed his army, and wherever Owain went with them he was victorious in battle. How this happened or why has been lost to tradition.

Owl of Cwm Cawlwyd. [W] One of the oldest creatures, who is unable to help Culhwch in his hunt for Olwen.