Proper noun
Proto-Algonquian
(linguistics) The theoretical proto-language of the Algonquian languages.
In Cheyenne, tone arose via vowel contraction; the long vowels of Proto-Algonquian contracted into high-pitched vowels in Cheyenne while the short vowels became low-pitched. Source: Internet
In the Proto-Algonquian example above, the choice of *m as the parent phoneme is only likely, not certain. Source: Internet