Translation according to P. W. Joyce:
Snauvbo in Galway, on the mainland beside the sea. Cows are put to graze on a little island a perch or two out, and made to swim across : hence Snámh-bo, swimming-place for cows. See Snakeel [reproduced below].
Snakeel in Cavan; Snámh-caol, narrow swim or swimming-place, a narrow deep ford that was crossed by swimming. See Snamh, vol. i. p. 365 [reproduced below].
When there were no means of making a river fordable, there remained the never-failing resource of swimming. When rivers had to be crossed in this manner, certain points seem to have been selected, which were considered more suitable than others for swimming across, either because the stream was narrower there than elsewhere, or that it was less dangerous on account of the stillness of the water, or that the shape of the banks afforded peculiar facilities. Such spots were often designated by the word snamh [snauv], which literally means swimming: a word often met with in out old historical writings in the sense of a swimming-ford, and which forms part of several of our present names. Lixnaw on the river Brick in Kerry, is called in the Four Masters Lic-snamha [Licksnawa], the flag-stone of the swimming; the name probably indicating that there was a large stone on the bank, from which the swimmers were accustomed to fling themselves off; and Portnasnow near Enniskillen (port, a bank), is a name of similar origin. About midway between Glengarriff and Bantry, the traveller crosses Snave bridge, where before the erection of the bridge, the deep transparent creek at the mouth of the Coomhola river must have been generally crossed by swimming. So with the Shannon at Drumsna in Leitrim; the Erne at Drumsna, one mile south-east of Enniskillen; and the narrow part of the western arm of Lough Corrib at Drumsnauv; all of which names are from the Irish Druim-snamha [Drum-snauva], the hill-ridge of the swimming-ford. When the article is used with this word snamh the s is eclipsed by t, as we see in Carrigatna in Kilkenny, which is in Irish Carraig-a'-tsnamha, the rock of the swimming; and Glanatnaw in the parish of Caheragh, Cork, where the people used to swim across the stream that runs through the glan or glen. In the north of Ireland the n of this construction is replaced by r (see p. 51 supra), as in Ardatrave on the shore of Lough Erne in Fermanagh, Ard-a'-tsnamha [Ardatnauva], the height of the swimming. Immediately after the Shannon issues from Lough Allen, it flows under a bridge now called Ballintra; but Weld, in his "Survey of Roscommon", calls it Ballintrave, which points to the Irish Bél-an-tsnamha [Bellantnauvna], the ford of the swimming, and very clearly indicates the usual mode of crossing the river there in former ages. A better form of this same name is preserved in Bellantra Bridge crossing the Black River in Leitrim, on the road from Drumlish to Mohill. The lower animals, like the human inhabitants, had often their favourite spots on rivers or lakes, where they swam across in their wanderings from place to place. On the shore of the little lake of Muckno in Monaghan, where it narrows in the middle, there was once a well-known religious establishment called in the annals Mucshnamh [Mucknauv], the swimming place of the pigs (muc, a pig), which has been softened to the present name Muckno. Some of our ecclesiastical writers derive this name from a legend; but the natural explanation seems to be, that wild pigs were formerly in the habit of crossing the lake at this narrow part. Exactly the same remark applies to the Kenmare river, where it is now spanned by the suspension bridge of the town. It was narrowed at this point by a spit of land projecting from the northern shore; and here in past ages, wild pigs used to swim across so frequently and in such numbers, that the place was called Mucsnamh or Mucksna, which is now well known as the name of a little hamlet near the bridge, and of the hill that rises over it, at the south side of the river.