Wikipedia
Manipravalam ( Macaronic) was a literary style used in medieval liturgical texts in South India, which used an admixture of Tamil and Sanskrit. Manipravalam is termed a mixture of Sanskrit and Tamil. Tamil language was the language of the region, part of Tamilakam, at the time of Manipravalam's genesis and use and its introduction caused a significant transition of Malayalam from Tamil in Kerala. Mani-pravalam literally means ruby-coral, where Mani means ruby in Tamil while Pravalam means Coral in Sanskrit. Malayalam is referred to as ruby and Sanskrit as coral. This was prevalent in Vaishnavite religious literature in Tamil Nadu and literary works in Kerala.
Since Tamil Vatteluttu did not have characters to represent some Sanskrit sounds, letters from the Grantha script were used to represent them. Native words and grammatical endings were written using Vatteluttu, and Sanskrit words were written using Grantha. Essentially, it was a hybrid script composed of Vatteluttu and the Grantha script.
A parallel literary tradition existed during the period that derived inspiration from the Tamil poetic tradition, known by the name pattu. Leelathilakam, a work on grammar and rhetoric, written in the last quarter of the 14th century in Kerala, discusses the relationship between Manipravalam and Pattu as poetic forms. It lays special emphasis on the types of words that blend harmoniously. It points out that the rules of Sanskrit prosody should be followed in Manipravalam poetry. This particular school of poetry was patronized by the upper classes, especially the Nambudiris. The composition of this dialect also reflects the way Aryan and Dravidian cultures were moving towards a synthesis.
Dramatic performances given in Koothambalams, known by the names of Koothu and Koodiyattam, often used Sanskrit and Malayalam. In Koodiyattom, the clown (vidooshaka) is allowed to use Malayalam while the hero recites slokas in Sanskrit. Tholan, a legendary court poet in the period of the Kulasekhara kings, is believed to have started this practice. The language of Kramadeepikas and Attaprakarams, which lay down the rules and regulations for these dramatic performances, is considerably influenced by the composite literary dialect of Manipravalam. Various hagiographies on the life of the Vaishnava saint Ramanuja were in manipravalam.