A 6th-century BCE lexicon created by the Hindu philologist Yaska. It is the oldest Indian treatise on etymology and semantics. In addition it contains one of the first attempts to organize words into lexical classes.

Example -
Yaska's four main lexical classes (i.e. word categories) are
(1) nama (substantives)
(2) akhyata (verbs)
(3) upasarga (prefixes), and
(4) nipata (invariant words, such as particles).

Etymology -
The word means "explanation" or "etymological interpretation" in Sanskrit.

Please comment