v1.0
Published 01/10/24
luaireag f. [ˈɫ̪uəɾʲaɡ̊], 
Cf. /Luərʲag/ (AFB˄).
gen. luaireig -[æɡ̊ʲ], -[ɛɡ̊ʲ], ‘storm petrel, Hydrobates pelagicus’ is listed by Fergusson (1886, 91), Forbes (1905, 33, 320) and Garvie (1999, 58). Fergusson also lists luaiseagan, which may be a typesetting error for luaireagan; Forbes includes both luaiseagan and luaireagan. The form luaireag is confirmed independently (e.g. MacCoinnich 1964, 206–09: Lewis; Faclan bhon t-Sluagh˄); luaireagan, if authentic, is conceivably for [ˈɫ̪uəɾʲaɡ̊an], with the nominally diminutive suffix -an, or [ˈɫ̪uəɾʲaɡ̊ən], with the plural ending -an. Forbes also lists SG loireag, which, given the fact that he ignores lengthmarks, might be for *lòireag, conceivably a by-form of luaireag, with ua ~ ò alternation, 
Cf. SG buaidheach ~ bòidheach ‘beautiful’ (SGDS Item 118) < buaidh ‘victory, success’ (< EG buaiḋ ‘victory; virtue; benefit’) + the adjectival suffix -ach.
or for loireag ‘water fairy’, an unconnected word.
According to Lockwood (1971, 27; cf. 1961, 37–38) SG loireag and luaireag are ‘(with diminutive -ag) apparently explicable as a misapplication of ON líri m. “nestling shearwater”’, cf. Far. líri m. ‘idem’. Thomson (1963, 340) excepts this association at face value; MacAonghuis (1971, 95) suggests that loireag is more likely to be a nickname in the sense ‘an te loireach’ (sic), 
I.e. an tè loireach ‘the ... one’; Dwelly gives loireach ‘soiled, as when a sheep’s wool is bedaubed with mud; state of not being dyed or barked brightly’; Faclan bhon t-Sluagh˄ gives loireach ‘drab, murky, muddy, discoloured (Harris), dirty, messy (idem), off colour, dull (Lewis)’.
adding that SG gobada-lìri ‘sandpiper’ occurs in Ross-shire (cf. Wentworth 2003, s.v. sandpiper: gobadá-lìridh [ɡ̊opətɑ ˈl’iːr’i], Gairloch 
Cf. Forbes 1905, 30: gobadaliri, gobhar-da-liri, 331: gobadail-iri; AFB: gobada-lìridh, Islay.
).
ON líri would formally yield SG *[ʎ̪iːɾʲə], and, albeit with the addition of the Gaelic suffix -ag, is unlikely to give SG luaireag. Neither is ON líri likely to be behind SG gobada-lìridh, which may be for SG *gobadan (< SG gob + the suffixes -ad + -an, cf. Ir. gobadán ‘sandpiper’), with final -n suppressed before the initial of an onomatopoeic element borrowed from Scots leerie ‘originally a meaningless word or element used for rhythmic purposes in children’s rhymes and as a suffix in such words as [gowkmaleerie] to denote sprightly, bustling motion, fanciful appearance or the like’ (SND˄).
In discussion, Ó Baoill (1978, 118) notes SG luatharan ‘sea lark’ (Armstrong 1825), luathrain ‘sandpiper’ (Fergusson ibid., 68) and luadhearan-glas (sic) ‘sanderling’ (ibid., 68).
Cf. MacDomhnuill 1741, 76: luatherein: ‘sea lark or sand laverock’; HSS 1828: luatharan ‘idem’; Forbes 1905, 33: luatharan ‘sea or sand lark, common sandpiper’; Dwelly 1911: ‘sea lark, sand lark, sandpiper’; MacLennan 1925: luatharan ‘sea lark’; AFB: idem ‘unspecific term for sandpipers and similar birds such as stints, knots and sanderlings’.
Armstrong also cites Ir. luatharan, but this is from O’Reilly’s (1817: luatharán ‘sea lark’) Irish dictionary, which most likely adopted the word from Shaw’s (1780: luatharan ‘sea lark’) Scottish Gaelic dictionary, although note Dinneen (1947): ‘luatharán “sea lark” (O’Reilly); cf. luathán “a bird” (Dúil Laithne [see Stokes 1872, 77: 123. luathan .i. en [leg. én] “avis” ...’. Ó Baoill also notes Dinneen’s Ir. (Omeath) luaireog ‘a species of gull’ (cited also in Ó Doibhlin 1997, 292, and Dunbar 2012, 90).
For the short unstressed syllable in Ir. luaireog, cf. (Omeath) cuinneog for cuinneóg ‘churn’ (LASID I, 21, Point 65).
SG luatharan and luaireag and Ir. luathán and luaireog may all derive from EG lúath ‘quick, swift’ (as HSS 1828 supposes for SG luatharan): lúath + -ar + -óc/-án, and have the general sense ‘speedy, nimble or active one’, cf. the derivative nouns SG luathaire ‘expedition, haste’, luathrachd ‘forwardness, quickness’, luathragan ‘haste, quickness’, luaithreachd ‘earliness’, luaithrean ‘haste, hurry’ and the adjective luaithreach ‘expeditious, active’ (Dwelly 1911), also luathair ‘speed’ (MacLennan 1925; Faclan bhon t-Sluagh˄: cha thill e air air a’ luathair [sic] ‘it will be a while before he returns’ and (s.v. siol-ghainmheach) cha tig acras air duine air luathair [‘a man in a hurray doesn’t feel hunger’], Lewis; McDonald 1972, s.v. luaitheir, luathar: cha n-fhàg a’ bhochdainne duine a’ luaithear [sic] [‘poverty does not leave a man quickly’], South Uist).
The origin of -(a)r in luatharan and luaireag is uncertain. There are a few other bird names with apparently similar suffixes: SG clacharan, cloichearan ‘stonechat’ (?< clach ‘stone’: → ‘the bird with a call like stones being tapped together’, cf. SG clachair ‘mason’ with the agentive suffix -air); *làparan, *làpairean (Forbes 1905, 32, who eschews lengthmarks, gives lapairin (along with laparan), so also An Stòr-Dàta 1993 and Garvie 1999, 58) ‘grebe’ (?< làb, làp etc. ‘mud, marsh’: → ‘the bird that forages in marshes’, but cf. SG lòbrach, lòbraich ‘marsh etc.’ (MacDonald 1946, 4; Cox 2002a, 60, 235) where -r- may be a suffix of place (-ar), or is perhaps intrusive); mionnaran ‘tit’, a variant of mion(n)tan (?< EG mind ‘crown, diadem’: → ‘the bird that wears a cap’) and pollaran, pollairean ‘dunlin’ (?< poll ‘mud; pool’: → ‘the bird that forages in pools’). (Note also SG seadaran ‘chirping of birds’ (Faclan bhon t-Sluagh˄: Lewis), which may be onomatopoeic or based on Eng. chatter.) The form -ar in some words is evidently a reflex of an adjectival ending, e.g. ceacharan ‘a venomous person’ (Faclan bhon t-Sluagh˄) < ceacharra ‘dirty, mean’ (EG cecharḋa) + -an, but in others any adjectival antecedent seems lacking: clabaran ‘the angler fish’ (?< clab ‘open mouth’: → ‘the fish that gapes’), màgaran ‘toad’ (?< màg ‘paw’: → ‘the creature that moves on (all) paws’, cf. màgair vb ‘to crawl’) and cìocharan ‘suckling child’ (?< cìoch ‘breast’: → ‘the child that suckles a breast’), where -aran conceivably goes back to the agentive suffixes -air + (nominally diminutive) -an; this might also be the case for clacharan, *làparan, mionnaran and pollaran. SG luaireag and luatharan may be based on luathair or luathaire (with the agentive suffixes -air and -aire, respectively), perhaps partly on clacharan etc.; yet cf. EG lúaiḋrén ‘act of moving, setting in motion etc.’ based on EG lúaḋ, verbal noun of luïḋ (lúaiḋiḋ) ‘moves’ (eDIL˄), with a notional *lúaiḋén yielding lúaiḋrén on the analogy of EG lúaithreḋ and its variant lúaithreán ‘ashes’, formed with the collective suffix -reḋ (Thurneysen 1975, 169); any connection with the personal ending of the deponent verb EG fo(r)-lúathar ‘flies’ (vn fo(r)lúaṁain) seems unlikely.