Term used by vyākaraṇin (native grammarians) since Patañjali to refer to the dialects prevalent in North India before the rise of the modern languages.
In Indology, it is used as an umbrella term for the dialects forming the transition between the late Middle and the early Modern Indo-Aryan languages, spanning the period between the 6th and 13th centuries CE. However, these dialects are conventionally included in the Middle Indo-Aryan period.
Apabhraṃśa in Sanskrit literally means "corrupt" or "non-grammatical language", that which deviates from the norm of Sanskrit grammar.
Apabhraṃśa literature is a valuable source for the history of North India for the period spanning the 12th to 16th centuries.
A significant amount of Apabhraṃśa literature has been found in Jain libraries. While Amir Khusrow and Kabir were writing in a language quite similar to modern Hindi, many poets, especially in regions that were still ruled by Hindu kings, continued to write in Apabhraṃśa. These authors include Saraha, Tilopa and Kanha of Kamarupa; Devasena of Dhar (9th century CE); Pushpadanta of Manyakheta (9th century CE); Dhanapal; Muni Ramsimha; Hemachandra of Patan; and Raighu of Gwalior (15th century CE).