Declension table of ?niṣṣidhvan

Masculine	Singular	Dual	Plural
Nominative	niṣṣidhvā	niṣṣidhvānau	niṣṣidhvānaḥ
Vocative	niṣṣidhvan	niṣṣidhvānau	niṣṣidhvānaḥ
Accusative	niṣṣidhvānam	niṣṣidhvānau	niṣṣidhvanaḥ
Instrumental	niṣṣidhvanā	niṣṣidhvabhyām	niṣṣidhvabhiḥ
Dative	niṣṣidhvane	niṣṣidhvabhyām	niṣṣidhvabhyaḥ
Ablative	niṣṣidhvanaḥ	niṣṣidhvabhyām	niṣṣidhvabhyaḥ
Genitive	niṣṣidhvanaḥ	niṣṣidhvanoḥ	niṣṣidhvanām
Locative	niṣṣidhvani	niṣṣidhvanoḥ	niṣṣidhvasu

Compound niṣṣidhva -

Adverb -niṣṣidhvam