unslumped
/ˈʌnˈslʌmpt/Definitions
1. adjective
not slumped or sagging; upright or erect
“The unslumped back of the chair provided excellent support for her tired body.”
2. verb
to straighten or become straight after being slumped
“After a good night’s sleep, she unslumped her shoulders and walked out of the room with a newfound confidence.”