Declension table of ?mahādruma

Neuter	Singular	Dual	Plural
Nominative	mahādrumam	mahādrume	mahādrumāṇi
Vocative	mahādruma	mahādrume	mahādrumāṇi
Accusative	mahādrumam	mahādrume	mahādrumāṇi
Instrumental	mahādrumeṇa	mahādrumābhyām	mahādrumaiḥ
Dative	mahādrumāya	mahādrumābhyām	mahādrumebhyaḥ
Ablative	mahādrumāt	mahādrumābhyām	mahādrumebhyaḥ
Genitive	mahādrumasya	mahādrumayoḥ	mahādrumāṇām
Locative	mahādrume	mahādrumayoḥ	mahādrumeṣu

Compound mahādruma -

Adverb -mahādrumam -mahādrumāt