Declension table of ?nirāntra

Neuter	Singular	Dual	Plural
Nominative	nirāntram	nirāntre	nirāntrāṇi
Vocative	nirāntra	nirāntre	nirāntrāṇi
Accusative	nirāntram	nirāntre	nirāntrāṇi
Instrumental	nirāntreṇa	nirāntrābhyām	nirāntraiḥ
Dative	nirāntrāya	nirāntrābhyām	nirāntrebhyaḥ
Ablative	nirāntrāt	nirāntrābhyām	nirāntrebhyaḥ
Genitive	nirāntrasya	nirāntrayoḥ	nirāntrāṇām
Locative	nirāntre	nirāntrayoḥ	nirāntreṣu

Compound nirāntra -

Adverb -nirāntram -nirāntrāt