Declension table of ?sumnya

Neuter	Singular	Dual	Plural
Nominative	sumnyam	sumnye	sumnyāni
Vocative	sumnya	sumnye	sumnyāni
Accusative	sumnyam	sumnye	sumnyāni
Instrumental	sumnyena	sumnyābhyām	sumnyaiḥ
Dative	sumnyāya	sumnyābhyām	sumnyebhyaḥ
Ablative	sumnyāt	sumnyābhyām	sumnyebhyaḥ
Genitive	sumnyasya	sumnyayoḥ	sumnyānām
Locative	sumnye	sumnyayoḥ	sumnyeṣu

Compound sumnya -

Adverb -sumnyam -sumnyāt