Aengus (Irish): Bastard son of Boann and the Daghda. Raised by Midir son of the Daghda.

Anu (Irish): The Morrigan as a kind and nurturing goddess.

Apple (General?): The fruit itself is associated with an acceptable fertility, not with a sinful transgression. It's blossom stood for purity and it's wood for integrity. In fact, wands were usually made from the wood of the Apple tree.

Ash Tree (General?): Tree that was held in high regard by the Celtic peoples. The rowan, or "mountain ash" was placed outside of household doors for protection and to link our world with the one beyond.

Badb (Irish): One of three sisters, or three aspects, of the Morrigan. A bloodthirsty shapeshifter, she is usually represented by either ravens or crows. Names very according to individual local traditions.

Belenus (Irish): Meaning "shining", his battles with Taranis cause the cycling of day and night.

Berba (Irish): Meaning "boiling", it gives it's name to the river Barrow, which is an anglicized form of Berba. For the mythology behind the term Berba, see Dian Cécht.

Boann (Irish): Celtic spirit of the river Boyne, Boyne being derived from Boann. Married to Nechtan. Boann became so turned on by Nechtan that she jumped into the water that was contained in his well of wisdom. Apparently, she was so hot that the water overflowed from the well, creating the river Boyne. After a couple years she became bored with Nechtan and fell in love with the Daghda, giving birth to a son named Aengus. He was fostered out to be raised by Midir, on of the Daghdas more official sons.

Cernunnos (Gallic): Male diety of agriculture and fertility, usually depicted as cross-legged and antlered.

the Daghda (Irish): The best known father of the masculine Celtic gods. A shape-shifter, like the Morrigan, he is a warrior usually depicted with a phallic (peanus) shaped weapon. The head of the weapon can kill many men at once, and the handle can bring the dead back to life. Thought of as living in the ground with the other Sídhe, with a tree, cauldron and tethered sow over top. Had a son named Midir and, with Boann, a son named Aengus.

Danu (Irish): Hypothetical goddess who is the female version of the Daghda. From Irish mythology.

Dian Cécht (Irish): Celtic god of healing. Used Berba to dispose of the burnt remains of three serpents, which came from the heart of an infant born of Morrigan after it was killed.

Dôn (Welsh): Welsh mother goddess, believed, by some, to be a variant of Anu.

Dru (General): see Oak.

Druid (General?): Derived from Dru, or "of the oak tree". Celtic religous leaders. see Oak.

Drunemeton (Asia Minor): Meaning "oak sanctuary", religous center of the Galatians.

Elder Tree (General): Sacred tree whose blossoms and berries were used in the making of sacramental wine, and was believed to ward evi, death and disease from humans and livestock .

Epona (Gallic): Gallic (Celtic) horse-goddess. Later became the patroness of Roman cavalrymen. She was protective and kind.

Fairy Folk: see Sídhe below.

Glanicae (Gallic): Trio of divine "mothers" resident in Glanum. See Glanis.

Glanis (Gallic): Masculine Celtic spirit. Gave the name Glanum, home of the Glanicae, to an ancient Celtic center before it was taken over by the Romans.

Hazel (General?): Tree that is associated with wisdom.

Macha (Irish): One of three sisters, or three aspects, of the Morrigan. A bloodthirsty shapeshifter, she is usually represented by either ravens or crows. Names very according to individual local traditions.

Midir (Irish): Son of the Daghda, raised the illegitimate son of Boann and the Daghda, Aengus.

Mistletoe (General?): Parasitic plant that lives on the top of oak trees. It's milk-colored berries signify fertility. In Pliny the Elders "Natural History" a ritual is described in which, on the sixth day of the new moon druids sacrificed two white bulls and made a potion from the mistletoe as a cure for barrenness.

the Morrigan (Irish): A war goddess whose symbol was the raven, sometimes even flocks of crows and ravens. Envisoned as both bird and women, it represented both an violent and destructive force as well as an imaginative force. At the same time it represents a creative force, since, in general, pagan mythologies assume a cycle construction in which ends always lead to beginnings. Indeed, she even gave birth, see Dian Cécht. Sometimes it is represented as being a trio of goddesses, namely: Badb, Macha and Nemain . When appearing as a kind and nurturing goddess she is knows as Anu.

Nantosulta (Gallic): Gallic (Celtic) raven goddess, closely associated with the Mavilly healing spring in Burgundy. Her husband was hammer-wielding Sucellos. Together with Sucellos, represented the complementary qualities of a couple, Nantosulta representing the feminine nature of such a relationship.

Nechtan (Irish): Husband of Boann. Archetypal god of water and sea, similiar to the roman Neptune.

Nehalennia (Gallic): A hunting goddess worshipped by tribes living along the northern coast of the Netherlands. Eventually becam a protector of Celtic seafarers.

Nemain (Irish): One of three sisters, or three aspects, of the Morrigan. A bloodthirsty shapeshifter, she is usually represented by either ravens or crows. Names very according to individual local traditions.

Oak (General?): Tree that symbolizes strength and solidity.

Rhiannon (Welsh): Welsh mother goddess.

Sabrina (British): Celtic spirit of the river Severn, Severn being derived from Sabrina. The main mythological story associated with Sabrina (latinized version of Welsh Hafren, British Sabren) is given in Book 2, Chapter 5 of "The History of the Kings of Britain". The following is from the Giles and Thompson translation (with my modifications):

As time continued its relentless march Corineus died, Locrin divorced Guendoloena and, following this, Estrildis was brought forward to be appointed queen. Guendoloena was furious when she heard this news and travelled to Cornwall, where she raised an opposition army against Locrin. A battle was eventually fought at the river Sture where, during the course of the battle, Locrin was killed by an arrow. Guendoloena then assumed the title of queen and ordered Estrildis and her daughter Sabre to be thrown into the river Severn. She decreed that the river be named after Sabre to remind all of her subjects of her deeds and the actions of the horrid Locrin.

Sequana (Gallic): Celtic spirit of the river Seine, Seine being derived from Sequana.

Sídhe (Irish): Exist in a world beyond, but near to, our world of the everyday. Also known as Fairy Folk, they usually emerge during the night, either kidnapping children or kidnapping beautiful women to be their wives. Recipients of their goodwill or jealousy, be it either individuals or families, can either experience a good life or a horrible life, respectively. At times the world of the Fairy Folk and our world touch and influence each other, when their influence is most felt. They tend to live underground and in groves, hillsides and bodies of water. Comes from that general, ill-defined body of material called Celtic mythology.

Souconna (Gallic): Celtic spirit of the river Saône, Saône being derived from Souconna.

Sucellos (Gallic): Gallic (Celtic) god, hammer-wielding husband of Nantosuelta. Associated by the Romans with their god Apollo, possibly in connection to the Mavilly healing springs in Burgundy, as Apollo was considered, among other things, as a god of healing. Together with Nantosulta, represented the complementary qualities of a couple, Sucellos representing masculine strength and protection.

Sul (British): Female Celtic spirit of the spring of Bath. Equivalent to the Roman goddess Minerva.

Taranis (Celtic): Celtic god of thunder, similiar to the Nordic god Thor, associated by the Romans with their god Jupiter. Believed to be the source of thunder and lightning. His continuing battle with Belenus, "shining", causes the cycling of day and night.

Tuatha Dé Danaan (Irish): A race of deities in their earliest forms but demoted to kings, queens, witches, giants and demons by later Christian monks.