unshrink
/ˈʌnˌʃrɪŋk/Definitions
1. verb
to restore something that has shrunk to its original size or shape
“She tried to unshrink the shrunken sweater, but it was beyond repair.”
2. noun
the process of restoring something that has shrunk to its original size or shape
“The unshrink process is often used to restore delicate fabrics.”