stiffen
//ˈstɪf.ən//
Verb
stiffenInfinitive
stiffenPresent tense
stiffenedPast tense
stiffenedPast participle
stiffeningPresent participle
stiffensThird-person singular
1
To make or become stiff, rigid, or less flexible.
The cold weather made my fingers stiffen.
2
To make or become stronger, firmer, or more resolute.
The bad news only stiffened her resolve to succeed.
3
To become tense or less relaxed, especially in response to fear, shock, or discomfort.
She stiffened when she heard the strange noise behind her.