Definitions

1. verb

to become or make less stiff or rigid; to relieve or reduce tension or stiffness

“The massage therapist instructed her client to breathe deeply to unstiffen her tense muscles.”

2. verb (transitive)

to relieve or reduce stiffness or tension in (something or someone)

“The physical therapist used various techniques to unstiffen her patient’s injured knee.”

3. verb (intransitive)

to become less stiff or rigid

“The injury in her back began to unstiffen over time, allowing her to move more freely.”

4. verb (transitive)

to make less stiff or rigid

“The new medication helped unstiffen the patient’s stiffened muscles.”