any of the vernacular Indic languages of north and central India (as distinguished from Sanskrit) recorded from the 3rd century BC to the 4th century AD
source: WordNet 3.0
Any one of the popular dialects descended from, or akin to, Sanskrit; -- in distinction from the Sanskrit, which was used as a literary and learned language when no longer spoken by the people. Pali is one of the Prakrit dialects.