Declension table of ?kūpayantra

Neuter	Singular	Dual	Plural
Nominative	kūpayantram	kūpayantre	kūpayantrāṇi
Vocative	kūpayantra	kūpayantre	kūpayantrāṇi
Accusative	kūpayantram	kūpayantre	kūpayantrāṇi
Instrumental	kūpayantreṇa	kūpayantrābhyām	kūpayantraiḥ
Dative	kūpayantrāya	kūpayantrābhyām	kūpayantrebhyaḥ
Ablative	kūpayantrāt	kūpayantrābhyām	kūpayantrebhyaḥ
Genitive	kūpayantrasya	kūpayantrayoḥ	kūpayantrāṇām
Locative	kūpayantre	kūpayantrayoḥ	kūpayantreṣu

Compound kūpayantra -

Adverb -kūpayantram -kūpayantrāt