Declension table of ?caṣṭavat

Masculine	Singular	Dual	Plural
Nominative	caṣṭavān	caṣṭavantau	caṣṭavantaḥ
Vocative	caṣṭavan	caṣṭavantau	caṣṭavantaḥ
Accusative	caṣṭavantam	caṣṭavantau	caṣṭavataḥ
Instrumental	caṣṭavatā	caṣṭavadbhyām	caṣṭavadbhiḥ
Dative	caṣṭavate	caṣṭavadbhyām	caṣṭavadbhyaḥ
Ablative	caṣṭavataḥ	caṣṭavadbhyām	caṣṭavadbhyaḥ
Genitive	caṣṭavataḥ	caṣṭavatoḥ	caṣṭavatām
Locative	caṣṭavati	caṣṭavatoḥ	caṣṭavatsu

Compound caṣṭavat -

Adverb -caṣṭavantam