Clauson (1972)
An etimological dictionary of pre-thirteenth-century Turkish
p. 609
kuğu:
‘swan’. S.i.m.m.l.g. as ku, sometimes only in ak ku ‘white swan’; NW Kumyk, Nog. kuv; SW Az. ğu; Osm. kuğu; Tkm. ğuv. L.-w. in Pe., etc., Doerfer III 1543. Türkü viii ff. (a man) kuğu: kuşka: soku:şmi:ş ‘encountered a swan’ IrkB 35; a.o. do. (ur-): Uyğ. viii ff. Civ. TT I 225 (uç-): Xak. xi kuğu: al-ḥawāṣil Kaş. III 225 (and 240, 25); there is considerable doubt of the exact meaning of this word which is also used to translate korda:y, q.v.; Red. 812 translates it, inter alia, as ‘pelican’ in Osm., but Brockelmann translates it as ‘swan’ in one place and ‘cormorant’ in the other: KB (geese, ducks and) kuğu 72; o.o. 365 (tü), 1101, 5377: xiv Muh. al-ğurnūq ‘stork, or crane ?’ (NB. not crane, which is turna:) ku:ku Mel. 73, 5; Rif. 176 (Rif. also ‘white water bird’ kuğu:): Xwar. xiv kuvu (misvocalized kavu) ‘swan’ Qutb 137; ditto (correctly vocalized but with -k- for -v-) 140; ku ‘swan’ MN 5: Kıp. xiv (in the list of birds) al-marzam ‘swan’ kuw Bul. 12, 3; ku: (?kuw) ditto (misvocalized al-mirzam ‘the star Rigel’) İd. 76: xv tamm ‘a kind of goose’ (Steingass) ku (in margin in second hand kuğı/kuğu) Tuh. 8b. 13.