In Early Irish literature a Bríatharogam is a two word kenning which explains the meanings of the names of the letters of the Ogham alphabet. Three variant lists of bríatharogaim or 'word-oghams' have been preserved, dating to the Old Irish period. They are as follows:
The first two of these are attested from all three surviving copies of the Ogam Tract, while the "Cú Chulainn" version is not in the Book of Ballymote and only known from 16th- and 17th-century manuscripts. The Auraicept na n-Éces or 'Scholars' Primer' reports and interprets the Bríatharogam Morainn mac Moín. Later Medieval scholars believed that all of the letter names were those of trees, and attempted to explain the bríatharogaim in that light. However, modern scholarship has shown that only eight at most of the letter names are those of trees, and that the word-oghams or kennings themselves support this. The kennings as edited and translated by McManus are as follows:
beithe means "birch-tree", cognate to Latinbetula. The kenning in the Auraicept is
:Feocos foltchain in beithi "of withered trunk fairhaired the birch"
luis is either related to luise "blaze" or lus "herb". The kenning
:Li sula luis ar ailleacht a caer " for eye is luis owing to the beauty of its berries"
fern means "alder-tree", Primitive Irish*wernā, so that the original value of the letter was . The kenning is
:Airenach Fiann air is di na sgeith "the van of the warrior-bands, for thereof are the shields"
sail means "willow-tree", cognate to Latin salix, with the kenning
:Li ambi.i. nemli lais.i. ar cosmaillius a datha fri marb "the colour of a lifeless one, i.e. it has no colour, i.e. owing to the resemblance of its hue of a dead person"
nin means either "fork" or "loft". The Auraicept glosses it as uinnius "ash-tree",
úath is unattested in inscriptions. The kenning "a meet of hounds is huath" identifies the name as úath "horror, fear", although the Auraicept glosses "white-thorn":
:comdal cuan huath ; no ar is uathmar hi ara deilghibh "a meet of hounds is huath ; or because it is formidable for its thorns."
dair means "oak".
:arirde dossaib duir "higher than bushes is an oak"
tinne from the evidence of the kennings means "bar of metal, ingot". The Auraicept equates it with "holly"
:trian roith tindi L.i. ar is cuileand in tres fidh roith in carbait "a third of a wheel is tinne, that is, because holly is one of the three timbers of the chariot-wheel"
coll meant "hazel-tree", cognate with Welsh collen, correctly glossed as cainfidh "fair-wood",
:coll.i. cach ac ithi a chno "coll, i.e. every one is eating from its nuts"
cert is cognate with Welsh pert "bush", Latin quercus "oak". It was confused with Old Irish ceirt "rag", reflected in the kennings. The Auraicept glosses aball "apple",
:clithar boaiscille.i. elit gelt quert "shelter of a boiscill, i.e. a wild hind is queirt, i.e. an apple tree"
muin: the kennings connect this name to three different words, muin "neck, upper part of the back", muin "wile, ruse", and muin "love, esteem". The Auraicept glosses finemhain "vine", with a kenning consistent with "love":
:airdi masi muin.i. iarsinni fhasas a n-airde.i. finemhain "highest of beauty is min, i.e. because it grows aloft, i.e. a vine-tree"
gort means "field". The Auraicept glosses "ivy":
:glaisiu geltaibh gort "greener than pastures is gort."
gétal from the kennings has a meaning of "killing", maybe cognate to gonid "slays", from PIE'. The value of the letter in Primitive Irish, then, was a voiced labiovelar, . The Auraicept glosses cilcach, "broom" or "fern":
:luth lega getal no raith "a leech's sustenance is getal."
straiph means "sulphur". The Primitive Irish letter value is uncertain, it may have been a sibilant different from s, which is taken by sail, maybe a reflex of /st/ or /sw/. The Auraicept glosses draighin "blackthorn":
:aire srabha sraibh "the hedge of a stream is sraibh."
ruis means "red" or "redness", glossed as trom "elder":
:ruamma ruice ruis "the redness of shame is ruis "
ailm is of uncertain meaning, possibly "pine-tree". The Auraicept has crand giuis.i. ochtach, "fir-tree" or "pinetree"
onn means "ash-tree", although the Auraicept glosses aiten "furze",
úr, based on the kennings, means "earth, clay, soil". The Auraicept glosses fraech "heath".
edad and idhad' are paired names of unknown meaning, although idhad may be a form of 'yew-tree', altered to make a pairing. The Auraicept glosses them as ed uath.i. crand fir no crithach "horrible grief, i.e. test-tree or aspen", and ibhar "yew", respectively.
Of the forfeda, four are glossed by the Auraicept, ebhadh with crithach "aspen", oir with feorus no edind "spindle-tree or ivy", uilleand with edleand "honeysuckle", and iphin with spinan no ispin "gooseberry or thorn".
