The Vaiyākaraṇasiddhāntabhūṣaṇa, also known as the Vaiyākaraṇabhūṣaṇa, is a commentary on the great 17th-century grammarian Bhaṭṭoji Dīkṣita’s Vaiyākaraṇamatonmajjana, written by Bhaṭṭọji’s nephew Kauṇḍabhaṭṭa. It is one of the most important texts of the late Pāṇinian grammatical tradition on questions of semantics. The main intention of Kauṇḍabhaṭṭa’s commentary is to refute objections raised by proponents of the two rival systems of Logic (Nyāya) and Exegesis (Mīmāṃsā) on various aspects of semantics, and to establish the Grammarians’ views on these subjects. The Vaiyākaraṇasiddhāntabhūṣaṇasāra, an abridged version of the Vaiyākaraṇabhūṣaṇa by the same author, is a popular work that was commented upon more than ten times. On the other hand, nobody so far has attempted to write a commentary on the Vaiyākaraṇabhūṣaṇa itself. The present work contains the Vaiyākaraṇabhūṣaṇa along with a commentary called Nirañjanī by Pandit Ramyatna Shukla and explanatory notes (Prakāśa) by the editor. This fourth and last part of the work discusses specific issues of semantics: the expressive power (śakti) of words, the meaning of negation, particles, abstract suffixes, etc. It also contains an extensive discussion of the philosophical concept of sphoṭa, one of the most fundamental notions introduced by the Pāṇinian tradition to account for the understanding of expressive units as undivided wholes.