Stiffening or rigidity (physical or figurative); becoming stiff or inflexible, e.g., body, expression, or policies becoming rigid.
寒さで手が硬直してしまった。
My hands stiffened from the cold.
会議中に彼の顔が硬直した。
His face stiffened during the meeting.
長年の慣例が組織の硬直を招いた。
Years of tradition led to organizational rigidity.