Declension table of ?masūsya

Neuter	Singular	Dual	Plural
Nominative	masūsyam	masūsye	masūsyāni
Vocative	masūsya	masūsye	masūsyāni
Accusative	masūsyam	masūsye	masūsyāni
Instrumental	masūsyena	masūsyābhyām	masūsyaiḥ
Dative	masūsyāya	masūsyābhyām	masūsyebhyaḥ
Ablative	masūsyāt	masūsyābhyām	masūsyebhyaḥ
Genitive	masūsyasya	masūsyayoḥ	masūsyānām
Locative	masūsye	masūsyayoḥ	masūsyeṣu

Compound masūsya -

Adverb -masūsyam -masūsyāt