Step 1: Understanding the Concept:
Nirukta is one of the six Vedangas (limbs of the Veda), specifically the one dealing with etymology and word-explanation. Authored by the sage Yaska, it is a commentary on a list of difficult Vedic words called the 'Nighantu'. The word 'Nirukta' literally means 'explained' or 'defined'. The science of Nirukta is based on the fundamental principle that all names (nouns) are derived from verbal roots. This etymological method is known as 'Nirvachana'.
Step 2: Detailed Explanation:
The 'Nirvachana-vidhi' is the core methodology used by Yaska to unlock the hidden meanings of the Vedic mantras. While Vyakarana (Grammar) focuses on the correct formation and syntax of words, Nirukta focuses on the semantic origin. Yaska argues that unless we know the 'why' and 'how' of a word's origin, we cannot fully grasp the intent of the sage who composed the mantra.
According to the Nirvachana-vidhi, every noun is linked to an action (Dhatu). For example, the word 'Agni' is derived from several roots: 'Agri' (meaning leading/first) because it is the first deity to be invoked, or from the root 'Ni' (meaning to lead). This method allows Yaska to provide interpretations even for archaic Vedic words that have fallen out of common usage. He establishes several rules for derivation: if the grammar is clear, follow it; if the grammar is not clear, look at the meaning; if only a syllable matches but the meaning is consistent, accept the derivation.
The Nirukta is divided into three sections: Naighantuka-kanda (synonyms), Naigama-kanda (difficult words), and Daivata-kanda (names of deities). In all these sections, the Nirvachana-vidhi serves as the investigative tool. This etymological science is considered the "Ear of the Veda" because it allows the student to hear the true semantic resonance of the sacred text. In the NTA syllabus, Yaska's Nirukta is a primary text, and understanding the 'Nirvachana' method is the first step in mastering etymological analysis. It distinguishes Nirukta from 'Nyaya' (Logic) or 'Ganana' (Counting) and establishes it as a unique linguistic discipline.
Step 3: Final Answer:
The method used in Nirukta is Nirvachana-vidhi. Thus, option (2) is correct.