Definitions

1. adjective

not stiff or rigid; relaxed or limp

“The unstiff fabric of the old blanket made it hard to hold its shape.”

2. adverb

in a relaxed or limp manner

“He walked unstiff through the park, taking in the sights and sounds.”

3. verb

to make or become less stiff or rigid

“The warm water helped to unstiff his sore muscles.”