Declension table of ?upaśayatva

Neuter	Singular	Dual	Plural
Nominative	upaśayatvam	upaśayatve	upaśayatvāni
Vocative	upaśayatva	upaśayatve	upaśayatvāni
Accusative	upaśayatvam	upaśayatve	upaśayatvāni
Instrumental	upaśayatvena	upaśayatvābhyām	upaśayatvaiḥ
Dative	upaśayatvāya	upaśayatvābhyām	upaśayatvebhyaḥ
Ablative	upaśayatvāt	upaśayatvābhyām	upaśayatvebhyaḥ
Genitive	upaśayatvasya	upaśayatvayoḥ	upaśayatvānām
Locative	upaśayatve	upaśayatvayoḥ	upaśayatveṣu

Compound upaśayatva -

Adverb -upaśayatvam -upaśayatvāt