Declension table of ?siddhyasiddhi

Feminine	Singular	Dual	Plural
Nominative	siddhyasiddhiḥ	siddhyasiddhī	siddhyasiddhayaḥ
Vocative	siddhyasiddhe	siddhyasiddhī	siddhyasiddhayaḥ
Accusative	siddhyasiddhim	siddhyasiddhī	siddhyasiddhīḥ
Instrumental	siddhyasiddhyā	siddhyasiddhibhyām	siddhyasiddhibhiḥ
Dative	siddhyasiddhyai siddhyasiddhaye	siddhyasiddhibhyām	siddhyasiddhibhyaḥ
Ablative	siddhyasiddhyāḥ siddhyasiddheḥ	siddhyasiddhibhyām	siddhyasiddhibhyaḥ
Genitive	siddhyasiddhyāḥ siddhyasiddheḥ	siddhyasiddhyoḥ	siddhyasiddhīnām
Locative	siddhyasiddhyām siddhyasiddhau	siddhyasiddhyoḥ	siddhyasiddhiṣu

Compound siddhyasiddhi -

Adverb -siddhyasiddhi