Declension table of ?iṣṭatara

Neuter	Singular	Dual	Plural
Nominative	iṣṭataram	iṣṭatare	iṣṭatarāṇi
Vocative	iṣṭatara	iṣṭatare	iṣṭatarāṇi
Accusative	iṣṭataram	iṣṭatare	iṣṭatarāṇi
Instrumental	iṣṭatareṇa	iṣṭatarābhyām	iṣṭataraiḥ
Dative	iṣṭatarāya	iṣṭatarābhyām	iṣṭatarebhyaḥ
Ablative	iṣṭatarāt	iṣṭatarābhyām	iṣṭatarebhyaḥ
Genitive	iṣṭatarasya	iṣṭatarayoḥ	iṣṭatarāṇām
Locative	iṣṭatare	iṣṭatarayoḥ	iṣṭatareṣu

Compound iṣṭatara -

Adverb -iṣṭataram -iṣṭatarāt