The opening pages of Yaska's Nirukta Vedanga text (Sanskrit, Devanagari script)
Nirukta (Sanskrit: निरुक्त, IPA: [nɪɽʊktɐ]) means "explained, interpreted" and refers to one of the six ancient Vedangas, or ancillary science connected with the Vedas – the scriptures of Hinduism. Nirukta covers etymology, and is the study concerned with correct interpretation of Sanskrit words in the Vedas.
Nirukta is the systematic creation of a glossary and it discusses how to understand archaic, uncommon words. The field grew probably because almost a quarter of words in the Vedic texts composed in the 2nd-millennium BCE appear just once.
The study of Nirukta can be traced to the last centuries of the 2nd-millennium BCE Brahmanas layer of the Vedic texts. The most celebrated scholar of this field is Yāska, who probably lived about the 5th century BCE, and wrote the Nighantu, the first book on this field. His text is also referred simply as Nirukta. The study of Nirukta has been closely related to the ancillary Vedic science of Vyakarana, but they have a different focus. Vyakarana deals with linguistic analysis to establish the exact form of words to properly express ideas, while Nirukta focuses on linguistic analysis to help establish the proper meaning of the words, given the context they are used in. Yaska asserts that the prerequisite to the study of Nirukta is the study of Vyakarana.
The texts of the Nirukta field of study are also called Nirvacana shastra. A critical edition of the Nighantu and the Nirukta was published by Lakshman Sarup in the 1920s.
Nirukta (Sanskrit), states Monier-Williams, means "uttered, pronounced, explained, expressed, defined, loud". It also refers to the etymological interpretation of a word, also the name of such works.
The related Sanskrit noun niruktiḥ means "poetical derivation" or "explanation of a word."