stiffen
UK: /ˈstɪf.ən/ | US: /ˈstɪf.ən/
vt. to make something rigid or less flexible
vi. to become rigid or less flexible
vi. (of a person or behavior) to become formal or tense
The word "stiffen" combines "stiff," derived from Old English stīf (meaning rigid or unbending), with the verb-forming suffix "-en," which originates from Old English -nian. This suffix was used to create verbs meaning "to make or become [adjective]." Over time, "stiffen" evolved to describe both literal hardening (e.g., materials) and metaphorical tension (e.g., behavior). The logic is straightforward: adding "-en" transforms the adjective "stiff" into an action.
The cold air caused the wet cloth to stiffen.
She felt her muscles stiffen after the long workout.
His smile stiffened when he heard the criticism.
Add starch to stiffen the fabric.
The government moved to stiffen penalties for fraud.