On p68 of Cnósach Focal ó Bhaile Bhúirne, there is this: is mairg a bhíonn i gcois aon-chaereach, or i gcois an aon-chaereach or i gcois an t-aon-chaereach. Has anyone got an idea what this might mean?

Maybe it means "woe to him who is so poor he has only a single sheep"?

A guess on my part would be the following: "There is sorrow in a one-sheeped measure of land" (i.e. a measure of land that could only sustain a single sheep). If someone owned only such a small plot of land, it would be a sign of extreme poverty.

"Cois" is the dative of "cos", meaning "foot" or "leg". However teanglann.ie gives the following secondary meanings: 7. ~ (talaimh), (a) small measure of land. (b)Hist: One forty-eighth of a ploughland. ~ mhóna, bank of turf. . I'm not really sure how a word that means "foot" or "leg" could also end up meaning a small measure of land.

Thank you. That makes sense!

The word for ploughland, of which cos was 1/48 was of course fearann. I'm still unsure of why this phrase says i gcois, why not go bhfuil cos aon-chaoireach aige, but it may just be an old phrase.

You could conceivably say "is mairg cos aon-chaereach a bheith agat" (there is sorrow in having a one-sheep plot of land).

Or you could say "is mairg a bhíonn i gcois aon-chaereach" (there is sorrow in a one-sheep plot of land).

In the latter case, Irish and English work the same way, i.e. the preposition ("i" in Irish, "in" in English) implies possession/having. .

More generally, the preposition "in" can be used to imply some other sort of association e.g. "there is pleasure in walking".

I see it now. I previously thought it elliptical for is mairg [don té] go mbíonn .... but it makes more sense without the don té in the sense you set out. Thank you.

The word "cos" has some other shades of meaning in teanglann.ie that imply either subordination or being physically beneath, which presumably come from the idea of the foot being at the base of the body.

3. (pl.) Underlings. Prov:Ná labhair leis na ~a má bhíonn an ceann sa láthair.
6. Lower end. ~ leapa, uaighe, foot of bed, of grave.

Following the same line of thinking, in the phrase "cos talaimh", "cos" could possibly be seen as meaning an inferior-sized portion.

Interestingly, Dineen has the following definition for "cos (talaimh)": grass of five cows.

Also, gníomh = 4 x cos

And fearann = 12 x gníomh (or 48 x cos), or in English, a ploughland.

Wikipedia defines a ploughland (aka carucate or carrucate) as a medieval unit of land area approximating the land a plough team of eight oxen could till in a single annual season. "A carucate might nominally be regarded as an area of 120 acres (49 hectares)." https://en.wikipedia.org/wiki/Carucate

Therefore one cos approximates to 2.5 acres. I don't really know anything about farming but I think I heard that one cow requires one acre of land. So, with one cos approximating 2.5 acres, this implies that one cos could sustain 2.5 cows, which is a little off Dineen's definition of a cos being a grass of five cows. (Of course, cows were smaller in the middle ages.) Anyway, that's the end of the maths lesson.

Just for fun, I stuck it in Google translate and got this:

It is woe to be in the presence of a single-minded person.