Dictionary Definition :
Definition[1]
:
The vernacular language of Magadha, the country of South Behar, called Māgadhī Prākrit, cf. 巴利 Pali, which is the language of the Ceylon canon. The Ceylon Buddhists speak of it as Māgadhī, but that was quite a different dialect from Pali.
Source
:
A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous