Editing Openai/69186d20-2d14-8013-b9c6-c09000f173f6 (section)

=== Assistant: 2511141431ET ===
251114_1431ET

short version: bainne is old and native Celtic, meaning “milk; milking; what is milked.” It goes back to Old Irish bainne, probably from a Proto-Celtic verbal noun meaning “a milking / that which is milked,” ultimately from a PIE root for “hit, strike, beat” used for “milking by squeezing.” Cognates show up in Welsh and Breton.

===== - bainne (noun, masc./neut.): “milk.” - bainne fuar – cold milk - uisce agus bainne – water and milk =====

Form-wise:
'' Modern Irish bainne < Old Irish ''bainne* “milk.”
* The -e ending is old; the -nn- is from a historical nasal cluster.
* Some analyses treat bainne as a verbal noun originally: “a milking, that which is milked,” later lexicalized as “milk (the substance).”

===== Most sources derive it from a Proto-Celtic base roughly of the form ''banjā / ''ban(j)o-, “milk, milking,” a deverbal noun. This is: =====
* Old Irish: bainne “milk.”
* Welsh: banw can mean a “sow” (not the same word), but for “milk/milking” the closer relatives are more technical; the clearest direct cognates are actually in the Goidelic branch (Irish/Scottish Gaelic/Manx): - Scottish Gaelic: bainne “milk” - Manx: bainne “milk”

So at minimum we have a Goidelic word family going back to Proto-Goidelic and Proto-Celtic. The P-Celtic branch generally uses other roots for “milk” (llaeth in Welsh, bleud in Breton, etc.), so this exact bainne word is Goidelic-specific, though the underlying verb root is older.

===== The usual reconstruction chain in the literature is: =====
'' Proto-Indo-European: a root like ''gwem- / *gwhen- “strike, squeeze, beat” used in a specialized sense “to milk (by squeezing/striking the udder).”
'' Proto-Celtic: a derivative ''ban-yo- / *banjā “milking; what is milked.”
* Old Irish → Modern Irish: bainne “milk.”

The semantic link “strike/squeeze → milk” is cross-linguistically common: milking is “squeezing/beating out” liquid. You see similar developments in other IE branches where verbs of “press/squeeze” yield nouns meaning “milk” or “cream.”

This PIE link is not as transparent as e.g. Latin lac vs Greek gála type families, but for Irish bainne the consensus is that it’s an old Celtic deverbal noun built on a “strike/squeeze” root, not a late loan.

===== - bainne is inherited Celtic, not a borrowing. =====
* It’s almost certainly originally a verbal noun “a milking / what is milked,” based on a Proto-Celtic verb “to milk/squeeze.”
* It’s Goidelic-wide: Irish / Scottish Gaelic / Manx bainne.
* Deeper ancestry points to a PIE root for “strike/squeeze”, re-purposed for “milking.”