ONlwSG

²buta m. [ˈb̥uʰt̪ə], 

Sometimes spelt buthta (e.g. Faclan bhon t-Sluagh^˄).

gen. idem., ‘fishing net buoy or float (traditionally made of sheepskin)’ 

For a description of its manufacture, see The Angus Macleod Archive, s.v. ‘buoys’^˄.

is recorded for Scalpay, Mull, Coll, Kintyre, Gigha, Arran (AFB^˄: /buhdə/), Barra, Tiree, Skye (AFB^˄: idem; Faclan bhon t-Sluagh^˄), St Kilda (AFB^˄: idem; Tobar an Dualchais^˄: ‘Cunntas air bàta-puist Hiort’ at 1:46 minutes), Benbecula (AFB^˄: idem; LASID IV, p. 238, Item 1123: [buːhṭə], long ?in error, [buxṭix´ən], short), South Uist (AFB^˄: idem; McDonald 1972), and puta [ˈpʰu̟ʰt̪ə] (Faclan bhon t-Sluagh^˄; AFB^˄: /puhdə/) and, with apocope, put [pʰu̟ʰt̪] (LASID IV, p. 257, Item 1123: [pʎhṭ]; Cox 1992, 138: [pʰʉʰt̪]) for Lewis. Armstrong (1825), HSS (1828), MacLeod and Dewar (1839) and Dwelly (1911) cite pùt, 

Although Dwelly notes that the word in Harris is put.

but, although followed by MacBain (1896; 1911) and Henderson (1910, 211), and although McDonald (2009) cites both pùt and puta, there seems to be no recent evidence of a long vowel.

Cox (ibid.) suggests that SG put (puta) is a loan from an unattested ON *putt-, comparing Norw. pute ‘pillow, cushion’, 

So also McDonald (2009).

while MacBain (ibid.) remarks that SG buta is ‘seemingly of Scand[inavian] origin’, comparing Sw. dial. puta ‘to be inflated’. 

So also Henderson (1910, 211).

However, Norw. pute is thought to have its origin in Dan. pude ‘pillow, cushion, pad’ (Ordbøkene^˄, s.v. pute; cf. Torp 1992, s.v. puta).

A derivation from Scots butty [ˈbʌti] ‘part of the entrails of an animal’ (Marwick 1929, s.v.) seems phonetically plausible. The word is compared with Norw. botn, along with the assimilated bott and derivatives botning, bytning, ‘the fourth stomach of a ruminant’ (Torp, s.v. botn, bytning), although ON botn m. in the sense ‘bottom, valley head etc.’ retains its nasal in the Orkney place-name Nether Button (Marwick 1952, 94), as it does in Shetland (Jakobsen 1928, s.v. *botn, *botten), which throws doubt upon a development directly from Old Norse (cf. bot). However, butty may be an assimilated form of (Shetland) botli [botli] ‘the cecum in sheep (the blind intestine, the beginning of the large intestine)’, which is either a reflex of ON *botni or an abbreviation of ON *botnlangi, cf. Norw. botnlange = botning (Jakobsen, s.v.).

A less likely possibility might be Scots (Orkney) poot [put], also pooty, pootie, ‘a young pig or kitten’ (SND^˄, s.v. ²poot), cf. (Shetland) putt, putti ‘a pet name for a cat’ (Jakobsen, s.v. putti), which is compared with Sw. dial. putte ‘a pet name for a little boy or small animal’ and Dan. idem ‘a pet name for a hen or (little) child’ (ibid.; cf. SND^˄, s.v. poot, and Torp, s.v. pŭte ‘kid goat’). If so, Scots poot (pooty, pootie) and/or putt (putti) may have been used descriptively or as a noa term for ‘a buoy’, cf. Scots (Shetland) pinni ‘a fishing buoy made of the inflated skin of an animal, generally with a small pin or pole on top, as a marker’, from ON pinni ‘a pin’ (Jakobsen, s.v. ¹pinni; SND^˄, s.v.).