IPA: /ˌʌnɪˈmædʒɪnətɪv/
KK: /ʌnɪˈmædʒɪnətɪv/
Lacking creativity or originality; dull and uninspired.
The movie was so unimaginative that I fell asleep halfway through.
Unimaginative → It is formed from "un-" (meaning not) and "imaginative" (from Latin "imaginari", meaning to form an image or to imagine). The word "unimaginative" means not having the ability to form images or ideas in the mind, thus lacking creativity or originality.
Think of 'not' ('un-') being added to 'imaginative', which means having the ability to create images or ideas. This helps you remember that 'unimaginative' describes someone who lacks creativity.