Definition of unmodernize in English:
unmodernize
verb (ˌ)ʌnˈmɒdənʌɪz(ˌ)ʌnˈmɒd(ə)nʌɪz
rare no object And with object. To give an old-fashioned appearance or form to (something); to make (something) no longer modern.
Origin
Early 19th century; earliest use found in John Keats (1795–1821), poet. From un- + modernize.