The Ogham Alphabet Explained

Ogham Standing Stone
Ogham Stone, Co. Kerry, Ireland. Photo: Keith Ewing

Ogham is an ancient alphabet that appeared in Ireland at least 1,600 years ago. It was used to inscribe Primitive Irish onto stone monuments, the oldest known form of the Gaelic languages.

The word ogham refers only to the form of the letters, while the letters themselves are known collectively as the Beith-luis-nin, these are the first three names of the letters in the ogham alphabet, in the same manner as the word alphabet derives from the first two names of the letters alpha and beta.

The ogham alphabet originally consisted of twenty distinct characters called feda “trees”, and arranged into four groups called aicme “families”The different groups correlate the direction of the strokes.

B Group – Right side strokes – Aicme Beithe

Ogham Letter Name Meaning
B beith birch
L luis flame/blaze or plant/herb
V/F fearn alder
S sail willow
N níon branch-fork

H Group – Left side strokes – Aicme hÚatha

Ogham Letter Name Meaning
H uath white-thorn
D dair oak
T tinne metal bar, ingot
C coll hazel
K ceirt bush

M Group – Across strokes – Aicme Muine

Ogham Letter Name Meaning
M muin neck, upper back
G gort field
NG nGéadal slaying/killing
Z straif sulphur
R ruis red

A Group – Notches (vowels) –  Aicme Ailme

Ogham Letter Name Meaning
A ailm unknown, pine?
O onn ash
U úr earth, soil
E eadhadh unknown
I iodhadh unknown

Supplementary Group – Forfeda

Five additional letters called forfeda were introduced mainly in the manuscript tradition several centuries after the peak of ogham usage. They appear to have represented sounds felt to be missing from the original alphabet

Ogham Letter Name Meaning
X/EA éabhadh unknown
OI óir gold
UI uilleann elbow
P, later IO pín, later iphín spine/thorn
CH/X, later AE eamhancholl twin-of-hazel
P peith birch

Peith , a late addition to the Forfeda, is a variant of Beith (B), with a phonetic value of [p]. It likely replaced Ifín , one of the “original” five Forfeda. Prior to the addition of the Forfeda to the original twenty letters, both [p] and [b] were probably symbolised by the same letter: Beith.


Here we have two decorative symbols often used at the start and end of inscriptions, and also a space symbol to separate words.

Ogham Letter Name Meaning
tús begin
spás space
críoch end