Clauson (1972)
An etimological dictionary of pre-thirteenth-century Turkish
p. 922
?D yalt
Hap. leg.; cf. yalım, also used w. kaya:; perhaps Dev. N./A. fr. 2 *yal-, and lit. ‘bare’, i.e. free of vegetation. Xak. xi yalt kaya: ‘a bare (or sterile, al-ṣald) rock’ (Kaş. al-cabal ‘mountain’); also used of anything massive (or solid, muṣmat) Kaş. III 7.