IPA: //ʌnˈslɪk//
KK: /ʌnˈslɪk/
Not smooth or polished; lacking in sophistication or style.
The presentation was quite unslick, with many rough edges and unrefined ideas.
Unslick → It is formed from "un-" (meaning not) and "slick" (from Old English *slicc*, meaning smooth or glossy). The word "unslick" means not smooth or glossy, indicating a lack of slickness.
Think of 'not' ('un-') being added to 'smooth' or 'glossy' ('slick') — that's why unslick means not smooth or glossy.