unable to be attacked, questioned, or defeated

हराना असंभव

English Usage: The team was unbeatable this season, winning every match.

Hindi Usage: इस सीजन टीम हरा पाना असंभव थी, हर खेल जीतते हुए।

Something that cannot be overcome or conquered.

अविजेयता

English Usage: The challenges he faced felt overwhelmingly unsurmountable.

Hindi Usage: जिन चुनौतियों का उन्होंने सामना किया, वे अत्यधिक अविजेयता से भरपूर थीं।