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Published 01/10/24
buanna m. [ˈb̥ũə̃ᵰ̪ə], gen. idem., also buannaidh m. [ˈb̥ũə̃ᵰ̪i], gen. idem., ‘billeted soldier’ (Shaw 1780 
So Armstrong 1825; and HSS 1828, also noting Lhuyd 1707 as a source.
); mercenary (HSS); billet-master; idler, straggler (McAlpine 1832); bully (Mackay 1829, 261, 352: buannaidh); one given to ostentation (Henderson 1910, 118)’. The sense idler is expanded in Mackenzie (1910, 384) to (Lewis) ‘an idle person who lives on the best that his neighbours can afford’.
So MacBain (1911), who cites McA[lpine].
For a probable instance of the sense (Harris, Scalpay) ‘old person receiving food charity’, see Faclan bhon t-Sluagh˄, s.v. buana.
SG buannaidh is derived by Mackay (1829, 261, 352: buani) from ON bóndi, búandi (also bóandi) m. ‘farmer; freeholder; husband; peasant’ (NO); so also Henderson (1910, 118: buanaidh), who compares Ir. buanna m. ‘billeted soldier; domineering person’ (Ó Dónaill 1977) and SG (Lewis) buana balaich ‘a fearless boy’; 
So also Ó Muirithe (2010, 22–23: buanaidh, buana).
SG buanna is similarly derived by Mackenzie (1910, 384), though recognising the change of meaning from Old Norse in Lewis usage. Although McDonald (≈2009, 344–45: buanaidh, buana balaich) considers the loan uncertain, he notes that the ‘semantic divergence is explicable on the basis of the range of possible meanings in the Old Norse form, from high status to a term of contempt’.
MacBain (1911: buana) appears to conflate etymologically buanna and the abstract noun buannachd f. ‘profit etc.’ with SG buain vb ‘to reap’, which derives from OG búain, the verbal noun of boingiḋ vb ‘breaks, smites, strikes; cuts, reaps; plucks, gathers; exacts, levies’ (eDIL˄).
SG/Ir. buanna is from EG búanna ‘a permanent, i.e. professional, soldier’, a nominal use of the adjective *búandae ‘permanent’, from búan adj. ‘lasting; constant etc.’ + the adjectival suffix -ḋ(a)e (Vendryes 1966; eDIL˄). The Early Gaelic suffix -ḋ(a)e yields a number of reflexes in modern Scottish Gaelic (Cox 1917, 152–53), e.g. SG daonna (daonda) adj. ‘human’ < OG doéndae (based on doén, a poetic form of OG duine m. ‘person’ (eDIL˄, s.v. doénda; Thurneysen 1976, 180, 220–21)), hence buanna, and SG nèamhaidh adj. ‘heavenly’, a metathesised form of OG neṁḋae (based on OG neṁ ‘sky; heaven’), hence buannaidh. Syntactically, Henderson’s SG buan(n)a balaich is comparable to expressions such as patan 
Cf. Scots pattin ‘little boy or girl’ (Jakobsen 1928; SND˄, s.v. †peiten).
balaich lit. ‘a youngster of a boy, a wee boy’ and rosad balaich lit. ‘a mischief of a boy’ (AFB˄).
Derivatives: buannachas m. ‘free quarters for soldiers in place of rent (McAlpine), billet (AFB˄)’; buannachd f. ‘quartering of soldiers’ (Shaw 
So Armstrong; HSS, also citing Lhuyd.
); gain, profit etc. (Dwelly; AFB˄)’; buannachdail adj. ‘profitable, emolumentary; available; useful; gratis, as a billet’; buannaiche m. ‘winner’ (AFB˄) and, with epenthetic t, buanntaiche m. ‘earner, winner; champion’ (ibid.).