ゆるぎない (translations)→ convincing unfailing unflinching unswerving
確固たる (translations)→ decided rigid rigorous solid unshakable
熱心に (translations)→ actively alertly assiduously attentively busy closely eagerly earnest faithfully fervently hard intently lively seriously vigorously
揺るぎない (translations)→ firm fully terrible unwavering