Declension table of ?mahātapana

Masculine	Singular	Dual	Plural
Nominative	mahātapanaḥ	mahātapanau	mahātapanāḥ
Vocative	mahātapana	mahātapanau	mahātapanāḥ
Accusative	mahātapanam	mahātapanau	mahātapanān
Instrumental	mahātapanena	mahātapanābhyām	mahātapanaiḥ mahātapanebhiḥ
Dative	mahātapanāya	mahātapanābhyām	mahātapanebhyaḥ
Ablative	mahātapanāt	mahātapanābhyām	mahātapanebhyaḥ
Genitive	mahātapanasya	mahātapanayoḥ	mahātapanānām
Locative	mahātapane	mahātapanayoḥ	mahātapaneṣu

Compound mahātapana -

Adverb -mahātapanam -mahātapanāt