> There are a couple of articles in Éigse on this, one by Ó Cuív in
> #8, and one by Greene in #12.
Ó Cuív agree with Dillon that "beirt = pair, two persons" comes from
"bert", but wonders if it isn't "bert = equipment" rather than "bert =
bundle" which gave rise to it. He argues demonstrates that the word
is attested earlier than Dillon thought, and gives citations, the
earliest being from Agallamh na Seanórach. He also quotes a passage a
LL (2133-6) "in which the word 'beirt' may possibly mean 'two persons'":
Uair is Patraic ro forcan
is friss daldait a torcrad
ro altaig beirt co mbalcblaid
do macaib Eirc is Olcan.
"The meaning of the whole quatrain is uncertain, and the sense of the
second couplet might be 'he thanked the sons of Erc and Olca for a
might famous deed'." - Ó Cuív
Greene goes along with Dillon and Ó Cuív, and further suggests that
"beirt = pair" may have come from the vocabulary of hunting, and esp.
falconry. He compares English "brace" and "couple" both of which
originally meant a leash holding two dogs, and "cast" which meant two
birds flown together. "Beart", he says, may have been the Irish
translation or equivalent of "cast", but "[f]ailing an example of
*beirt sheabhac or *beirt fhabhcún 'a cast of hawks, falcons', this is