noun which may take the genitive case particle 'no', noun
unshakeable; steadfast; firm; absolutely secure
Describes a belief, attitude, support, or position that is completely unwavering and cannot be moved. Often used in formal or written contexts.
His unshakeable conviction never wavered in the face of any hardship.
この計画には確固不動の支持が必要だ。
This plan needs steadfast support.