Boukólos rule

The boukólos rule is a phonological rule of the Proto-Indo-European language (PIE). It states that a labiovelar stop () dissimilates to an ordinary velar stop () next to the vowel or its corresponding glide . The rule is named after an example, the Ancient Greek word βουκόλος (; from Mycenaean Greek qo-u-ko-ro /gwou̯kolos/) "cowherd", ultimately from PIE , dissimilated from . If the labiovelar had not undergone dissimilation, the word should have turned out as *, as in the analogously constructed αἰπόλος () "goatherd" < . The same dissimilated form is the ancestor of Proto-Celtic , the source of Welsh bugail (which would have had -b- rather than -g- if it had come from a form with *-kw-) and Irish buachaill, which is the common word for "boy" in the modern language. Another example could be the Greek negation οὐκ[ί] (), which Warren Cowgill has interpreted as coming from pre-Greek *ojukid < , meaning approximately "not on your life". Without the boukólos rule, the result would have been *οὐτ[ί] ().