Is the Turkic us- ‘to be thirsty’ a loanword from Mongolic? An overview of Mongolic loanwords in Old Turkic

The present study questions whether the Old Turkic verb us- ‘to be thirsty’ is derived from the nominal base *u ‘water’, which is attested as such in Kitan and as *usun in Common Mongolic. Since there is no denominal verbal formative +s- in Turkic, us- must be regarded as a simplex. Since both *u ‘water’ and +(A)s- are present in Mongolic, the Turkic verb is considered to be a loanword from Pre-Proto-Mongolic *us-, which was replaced in Proto-Mongolic by *umdaas- ‘to be thirsty’.