stiffen
Definition
To become or make something become rigid or less flexible.
日本語 硬い、または柔軟性が低いものになる
Example
"She stiffened her posture when the boss entered the room."
To become or make something become rigid or less flexible.
日本語 硬い、または柔軟性が低いものになる
"She stiffened her posture when the boss entered the room."