Clauson (1972)
An etimological dictionary of pre-thirteenth-century Turkish
p. 289
D 2 uzan-
Refl. f. of uza:-; ‘to be long, stretched out’, and the like. First noted in (Xak.) xiii(?) Tef. 322, Kıp. xiii Hou. 41, 21; Osm. xiv ff. TTS I 737, etc. Survives in some NW and SW languages.