IPA: /ʌnˌɛkstrəˈɔːrdɪnəri/
KK: /ʌnˌɛkstrəˈɔrdəˌnɛri/
Something that is not remarkable or special; it is common and unremarkable.
The movie was unextraordinary, lacking any exciting moments.
Unextraordinary → It is formed from "un-" (meaning not) and "extraordinary" (from Latin "extraordinarius", meaning outside the ordinary). The word "unextraordinary" means not outside the ordinary, or simply ordinary.
Think of 'not' ('un-') being added to 'outside the ordinary' ('extraordinary') — that's why unextraordinary means something that is just ordinary.