Declension table of ?kupana

Masculine	Singular	Dual	Plural
Nominative	kupanaḥ	kupanau	kupanāḥ
Vocative	kupana	kupanau	kupanāḥ
Accusative	kupanam	kupanau	kupanān
Instrumental	kupanena	kupanābhyām	kupanaiḥ kupanebhiḥ
Dative	kupanāya	kupanābhyām	kupanebhyaḥ
Ablative	kupanāt	kupanābhyām	kupanebhyaḥ
Genitive	kupanasya	kupanayoḥ	kupanānām
Locative	kupane	kupanayoḥ	kupaneṣu

Compound kupana -

Adverb -kupanam -kupanāt