Clauson (1972)
An etimological dictionary of pre-thirteenth-century Turkish
p. 114-115
D ögrün-
Refl. f. of ögir-; survives in NE Kız., Koib., Sag. ürin- R I 1834, Khak. örin- Bas. 136, 256. Uyğ. viii ff. Bud. ögründe[çi] (sic) erklig [gap] ‘the joyful independent . . .’ U II 63, 5 (i).