Declension table of ?siddhimanvantara

Neuter	Singular	Dual	Plural
Nominative	siddhimanvantaram	siddhimanvantare	siddhimanvantarāṇi
Vocative	siddhimanvantara	siddhimanvantare	siddhimanvantarāṇi
Accusative	siddhimanvantaram	siddhimanvantare	siddhimanvantarāṇi
Instrumental	siddhimanvantareṇa	siddhimanvantarābhyām	siddhimanvantaraiḥ
Dative	siddhimanvantarāya	siddhimanvantarābhyām	siddhimanvantarebhyaḥ
Ablative	siddhimanvantarāt	siddhimanvantarābhyām	siddhimanvantarebhyaḥ
Genitive	siddhimanvantarasya	siddhimanvantarayoḥ	siddhimanvantarāṇām
Locative	siddhimanvantare	siddhimanvantarayoḥ	siddhimanvantareṣu

Compound siddhimanvantara -

Adverb -siddhimanvantaram -siddhimanvantarāt