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.
彼の確固不動の信念は、どんな困難にも揺るがなかった。
His unshakeable conviction never wavered in the face of any hardship.
This plan needs steadfast support.