firmly; resolutely; decisively
Expresses a strong, unwavering attitude or action; often used when refusing, asserting, or taking a stand.
He firmly refused the offer.
The government is determined to push forward with reforms.
断固として stresses firm, unwavering resolve behind an action, while 断じて emphasizes the absolute certainty of a statement or denial.
From 断固 (firm, resolute) + として (adverbial particle). 断固 is a Sino-Japanese compound of 断 (decisive) and 固 (firm).