From Middle English *linne, from Old English hlynn (“torrent”).
Meanings
(Northern-England, Scotland, Wales) A waterfall or cataract (torrent of water running over a rocky bed), or a ravine down which such a waterfall rushes.
And the roaring of the linn. 1866, John Harland, Lancashire Lyrics: Modern Songs & Ballads of the County Balatine, section 85:
Hear! now, Yon linn's melodious thunder! 1896, Lewis Proudlock, The Borderland Muse, page 51:
"For it's o'er the bank, and it's o'er the linn,
"And it's up to the meadow ridge—"
"Ay," quo' the Stumpie hirpling in, 1844 December, “The Legend of Stumpie's Brae”, in The Dublin University Magazine, page 720:
What seek we here / Amid this waste where desolation scowls, / And the red torrent, brawling down the linn, / Sings everlasting discord? 1814, J. H. Craig [pseudonym; James Hogg], The Hunting of Badlewe: A Dramatic Tale, London: H[enry] Colburn; Edinburgh: G. Goldie, →OCLC, page 1; quoted in “The Hunting of Badlewe, a Dramatic Tale. 8vo. Edin. 1814. [From the Scottish Review.]”, in The Analectic Magazine, Containing Selections from Foreign Reviews and Magazines, together with Original Miscellaneous Compositions, volume V (New Series), Philadelphia, Pa.: Published and sold by Moses Thomas, […], May 1815, →OCLC, pages 353–354:
From Scottish Gaelic or Irish linn (“pool, pond”), or else a Brythonic source such as Cumbric *lınn, all from Proto-Celtic *lindos (“lake, liquid”). Conflated to some extent with linn (“waterfall”).
Meanings
(Northern-England, Scotland, Wales) A pool of water, especially one formed and agitated by the water from a cascade.
A trellised path led down into the valley of the brook, and he turned to follow it. The stream was a breakneck, boiling Highland river. Hard by the farm, it leaped a little precipice in a thick grey-mare's tail of twisted filaments, and then lay and worked and bubbled in a linn. Into the middle of this quaking pool a rock protruded, shelving to a cape; and thither Otto scrambled and sat down to ponder. 1885, Robert Louis Stevenson, Prince Otto:
His successful angler landing the linn-lier [fish that inhabits a pool of water]. 1894, Furth, Haliburton, section 177:
There frisks the freckl'd finny tribe,
In linns both wide and steep. 1812, “Poems”, in Forbes, section 49:
The running of deep water in a linn. 1896, Crockett, Grey Man, vii
The pool is there — the true linn, in the original acceptance of the word — dark and bottomless. 1868 September 24, James Hardy, addressed delivered at Chirnside, quoted in the History of the Berwickshire Naturalists' Club, volume 5, page 386
In the clear linn the trouts shuttled from stone and crevice. 1823, Galt, Gilhaize, section XXVIII: