Tatsama (Sanskrit: तत्सम IPA: [tɐtsɐmɐ], lit. 'same as that') are Sanskrit loanwords in modern Indo-Aryan languages like Bengali, Marathi, Odia, Hindi, Gujarati, and Sinhala and in Dravidian languages like Malayalam and Telugu. They generally belong to a higher and more erudite register than common words, many of which are (in modern Indo-Aryan languages) directly inherited from Old Indo-Aryan (tadbhava). The tatsama register can be compared to the use of loan words of Greek or Latin origin in English (e.g. hubris).
The origin of tatsamas (Bengali: তৎসম, romanized: tôtsômô) in Bengali is traced to 10th century Brahmin poets, who felt that the colloquial language was not suitable for their expressive needs. Another wave of tatsama vocabulary entered the then Bengali language by Sanskrit scholars teaching at Fort William College in Kolkata at the start of the 19th century. The textbooks used in these courses paved the way for more tatsama words entering common usage.
Bengali's lexicon is now about 40% tatsama (with about 58% tadbhava vocabulary inherited from Old Indo-Aryan via the Prakrit languages such as Apabhramsha and Avahațțha). Writers such as Rabindranath Tagore, Michael Madhusudan Dutt, Ramram Basu, Ishwar Chandra Vidyasagar, and Bankim Chandra Chattopadhyay introduced a large number of tatsamas into Bengali.
Early Odia dictionaries such as Gitabhidhana (17th Century), Sabda Tattva Abhidhana (1916), Purnachandra Odia Bhashakosha (1931) and Promoda Abhidan (1942) list Sanskrit Tatsama vocabulary.
They are derived from Sanskrit verbal roots with the addition of suffixes and known in Odia as "tatsama krudanta".
Relation of Malayalam with Sanskrit started around AD 15 century only. Prior to that, the language prevailed at present Kerala which was ancient Chera Land was totally Dravidian. Yet, Malayalam has very strong relation with Sanskrit due to Manipravalam, than any other Indian languages. Malayalam derived many letters (alphabets/syllables), words, grammatical rules etc from Sanskrit. This relation started due migration of Buddhist monks and Hindu Brahmins from Northern India and expanded to Punjabi and Marathi refugees which was given shelter in Kerala by the benevolent kings.
Malayalam has many tatsama words, which is used in local written and spoken form depending on the region of Kerala.
Many more Sanskrit words are in the Malayalam Dictionary.
The way the tatsama entered the Sinhala language is comparable to what is found in Bengali language: they are scholarly borrowings of Sanskrit or Pali terms. Tatsama in Sinhala can be identified by their ending exclusively in -ya or -va, whereas native Sinhala words tend to show a greater array of endings. Many scientific concepts make use of tatsama, for instance grahaņaya 'eclipse', but they are also found for more everyday concepts.
Sanskrit influenced the Telugu language for about 500 years. During 1000-1100 AD, Nannaya's Telugu in Mahabharata, Telugu in several inscriptions, Telugu in poetry reestablished its roots and dominated over the royal language, Sanskrit. Telugu absorbed the Tatsamas from Sanskrit.
Metrical poetry in Telugu ('Chandassu') uses meters such as Utpalamala, Champakamala, Mattebham, Sardoola, Sragdhara, Bhujangaprayata etc.. which are pure Sanskrit meters.
Telugu has many tatsama words, known as prakriti. The equivalent colloquial words are called vikrutis, meaning "distorted". Prakriti are used only as a medium of instruction in educational institutions, offices etc. Today, spoken Telugu contains both prakruthi and vikruthi words.