Jeseri is a language derived from old Malayalam, spoken in the Union Territory of Lakshadweep

Lakshadweep

Lakshadweep , formerly known as the Laccadive, Minicoy, and Amindivi Islands, is a group of islands in the Laccadive Sea, 200 to 440 km off the coast of the South West Indian state of Kerala...

 in India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

. It is closely related to Malayalam, Tamil

Tamil language

Tamil is a Dravidian language spoken predominantly by Tamil people of the Indian subcontinent. It has official status in the Indian state of Tamil Nadu and in the Indian union territory of Pondicherry. Tamil is also an official language of Sri Lanka and Singapore...

 and Kannada.
It is spoken on the islands of Chetlat, Bitra, Kiltan, Kadmath, Amini, Kavarathi, Androth, Agathi, and Kalpeni, in the archipelago of Lakshadweep. Each of these islands has its own dialect. It is hard for a speaker of Malayalam to understand Jeseri, more so, in the case of the idiom spoken by the older people.

The phonology of Jeseri is similar to that of Malayalam, except that a significant influence from Urdu (Hindi, Persian, and Arabic combined) is clearly evident. As for the vocabulary, earlier, Urdu words were widely used; but now, more words from Malayalam can be found.

Reference