Anthropomorphic:
Used in the context of Neolithic art, it refers to art that forms a human  silhouette or displays some kind of human characteristic, often facial.

Aengus Og:
In myth Aengus, the son of the Daghda, was a god of love and youth who dwelled within the mound of  Newgrange.

Archaeoastronomy:
A recent development in Archaeology dealing with the astronomical aspects of   ancient monuments. This includes the  alignment of structures to the sun, moon and planets and the possible link of Neolithic art to the celestial realm.

Beaker period:
A transition period in archaeology between the Neolithic and the  Bronze age (2300-2000BC approx.)this period is characterised by highly ornamented flat-bottomed vessels. The classic Beaker burial is one of inhumation, the deceased accompanied by a beaker or drinking vessel, wristguard and copper knife.

Bronze age:
A period in archaeology running from around 2000- 600BC which saw the introduction of smelting techniques and production of metal, though stone implements were still the most prevalent.

Boann:
In myth Boann was a white cow goddess ( Bo Fionn) who was manifest in the river  Boyne. Originally married to the druid Elcmar, she became the consort of the Dagdha and by him the mother of Aengus Og.

Chevron:
A common motif in Neolithic art, the zigzag pattern.

Cup marks:
Small depressions, normally circular, found on the structural stones at Newgrange. It is very difficult to say if they are wholly natural or whether they have been worked by human hand. Their function, if indeed they had one, is unknown.

Cursus:
An area defined by 2 lines of bank and ditch often ending or aligned on a monument or landscape focus. There is still debate as to when they were built and what their function was.

Dendrochronology:
Also known as tree ring dating,

Daghda mór:
In myth,  the great or good god. A god of abundance with a cauldron of plenty often   portrayed as a pot-bellied trickster. He is associated with many river goddesses and was a prime deity for the Celts. 

Drystone construction:
A method used in building where small cut stones without binding agents are employed. A good example of this is the passage tomb of Maes Howe,Orkney Islands, Scotland.

Elcmar:
In myth Elcmar was the first dweller in Si an Bhru

Earth energies:
Some people believe that Newgrange was deliberately sited on a ley or energy line.Several dowsers have claimed that the site generally and chamber specifically react very strongly to divining rods.

Folly:
A foolish or whimsical building. Some were built as status symbols, others to employ starving tenants and peasantry during the famine years. The Newgrange folly is believed to date from the mid 1800s and was built from cairn material. 

Greywacke:
A greyish green sandstone which constitutes the majority of the structural stones of Newgrange. 

Henge monument:
Often called an embanked enclosure, a henge is characterised by a bank composed of material scarped up from the interior and the enclosed area, normally circular, remaining domed in shape. They are often linked to passage tombs, an excellent example is the Dowth henge.

Iron age:
Period following the Bronze Age. The Iron Age was the stage in the development of any people in which tools and weapons whose main ingredient was iron were prominent. The adoption of this material often coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles. In Ireland from 500BC until early medieval Period.

Lintel:
A flat stone covering a door way. At Newgrange, this is the decorated stone positioned above the roof box noted for its dived diamond design.

Lugh:
A prime god of the Tuatha De Danaan, also known as  Lugh lamh fhada An Samildanach An Lu

Lozenge:
The diamond pattern found in Neolithic art.

Mesolithic:
From the Greek meaning Middle Stone. Refers to the period prior to the introduction of farming. C 8000-4000BC

Neolithic:
New Stone Age. Coincides with the introduction of farming in Ireland and runs up to the  Bronze Age. C4000-2000BC 

Orthostat:
Another name for the upright stones lining the passage and chamber of the tomb.

Pick dressing:
A technique used by Neolithic artists whereby the surface of stones were 'dressed' using a stone chisel to pick or pock out the stone.

Paleolithic:
Literally Old Stone Age refers to the period following the last Ice Age.

Radio Carbon dating:
A scientific technique developed in the 1940's whereby it is possible to date organic material according to the carbon 14 content

Revetment:
Retaining wall or facing

Sill stones:
Horizontal stones which separate the recess from the chamber area, the chamber area from the passage or divide the passage into sections.

Souterrain:
Generally early Christian period, (5th to 12th Century). An underground structure consisting of one or more passages or chambers. They are normally of drystone construction and were used for storage and possibly escape routes. The mounds at Knowth and Dowth contain souterrains 

Tuatha De Danaan:
The People of the Goddess Danu, a race of super-natural beings who according to tradition ruled Ireland before the coming of the Celts and afterwards retreated into the fairy mounds and forts. 

Undifferentiated:  
A type of passage tomb consisting of a passageway which gradually rises to a chamber, no recesses are present.