uncool /ʌnˈkuːl/adjective 1noun 1forms 4 adjective1 •(slang) Not in accord with the current fashion, standards, or mores of a particular group; not cool.It's not the coolest pad in Melbourne. Your presence is enough to make it more than a little uncool. — 1970 noun1 •(slang) The quality of being uncool.Not surprisingly, they discover that despite its sleek exterior, the interior of cool is as warm as a puppy. It is the very essence of “uncool,” in fact: […] — 2000 formsmore uncool · uncooler · most uncool · uncoolest