ONlwSG

ruideag f. [ˈɍu̟d̥ʲaɡ̊], [ˈɍɯ̟d̥ʲaɡ̊], 

Cf. [ru̜dʹɑɡ] (Faclan bhon t-Sluagh^˄: Lewis); /Rudʲag/ (AFB^˄).

gen. ruideige -[æɡ̊ʲə], -[ɛɡ̊ʲə], ‘kittiwake, Rissa tridactyla’. The term ruideag has been recorded in Scalpay (AFB^˄), Lewis (ibid.; Faclan bhon t-Sluagh^˄), Harris, South Uist (ibid.) and St Kilda (Mackenzie 1905, 77), and is cited by Fergusson (1886, 88), Forbes (1905, 35, 298), Dwelly (1911), MacLennan (1925), Cunningham (1990, 127) and Garvie (1999, 62). Writing in Gaelic about St Kilda, MacFhearghuis (1995, 20, 59) uses the spelling ruiteag, but this is his own form and may be the result of confusion with SG ruiteag ‘blush, redness’; cf. also Sgeir nan Ruiteag, besides Sgeir nan Ruideag ‘the skerry of the kittiwake’, listed in Faclan bhon t-Sluagh^˄ (cf. OS 1843–82 Sgeir na’ Ruideag NG431981).

A Lewis variant riodag [ˈɍid̪̥aɡ̊] is noted by Mackenzie (1910, 385) and MacBain (1911), and seems to be being implied by the unconventional spelling rittag (Christiansen 1938, 4, 16). All three authorities derive riodag from ON rytr m. ‘idem’; so also de Vries (1962) and McDonald (2009, 397; 2015a, 128 

Among his Scottish Gaelic forms, McDonald cites riotach, but this is erroneous (pers. comm. Dr Roderick McDonald).

). ON rytr is thought to be of onomatopoeic origin (Lockwood 1961, 45).

ON ryt acc. (with a round front vowel) yields either SG [ˈɍid̪̥] or [ˈɍu̟d̥ʲ] (later [ˈɍɯ̟d̥ʲ]). In the former, fronting is preserved in SG /i/ and rounding subsumed in non-palatal /d/; 

Cf. ON *Fylsklettar pl. ‘(the) cliffs of the colt’ > SG Fileascleitir [ˈfilə ˌs̪kleʰtʲəɾʲ] (Cox 2022, 167–68, 715–78), with a phonetically non-palatal although phonemically palatal rather than non-palatal lateral.

in the latter, rounding is preserved in SG /u/ and fronting transferred to palatal /d´/.

Cf. ON *Brynugil > SG Bruinigil ‘(the) ravine of the river *Bryna’ [ˈb̥ɾɯ̟̃nə ˌɡ̊ʲil] (Cox 2022, 169–70, 567–68), with [n] /n/ < [nʲ] /n´/, after the latter fell together with the former.

The latter is recorded in Scalpay (AFB^˄: ruid), otherwise they survive only in the derived forms riodag, ruideag, with the diminutive suffix -ag, no doubt by association with other bird names, e.g. asaileag, q.v., arspag, q.v., and dìdeag (s.v. dìrid). Cf. Scots (Orkney) ritto and the diminutive form rittock 

Lockwood (1961, 44) writes, ‘Or[kney] ritto, with secondary diminutive suffix rittock’, although, while final -o commonly develops into -ick or -ock in parts of Orkney (Marwick 1929, xxix), ritto might simply be a reflex of earlier *ritta (cf. Far. rita, Ice. ryta ‘kittiwake’ (ibid.)).

‘black-headed gull; tern; kittiwake’ (Marwick 1929, s.v. ritto; SND^˄, s.v. idem), and (Shetland) rippock, rippek (Jakobsen 1928, s.v. rippek; SND^˄, ibid.), although Jakobsen is reluctant to see rippek as a corruption of (Shetland) *rittek.

Lockwood notes that SG riodag ‘has a diminutive suffix like the Orkney and Shetland forms’, and continues that it is noteworthy ‘that both Scots Gaelic and Norn show such a remarkable extension of the diminutive suffix -ag/-ek etc., a development which marks off the former from Irish and the latter from the other Scandinavian languages. Perhaps the impetus in this development came to both from Lowland Scots.’ However, the suffix -ock/-e(c)k is certainly Scots, while the suffix -ag is simply the Scottish Gaelic reflex of EG -óc. Although it is impossible to say for certain that neither rittock or riodag influenced the other, it is perfectly possible they developed as shown.

Finally, post-stress ON -t yields SG -d regularly, cf. ON fit > SG fid, q.v.