The word "unbelievable" means that something is difficult to accept or hard to believe because it seems strange, amazing, or impossible. Full definition
That's why internet acne forums are full of people with unbelievable sounding stories of individual foods, including oranges, breaking them out. (supernaturalacnetreatment.com)
Single - use - plastics are particularly problematic because they are often small, light enough to float and be transported by wind and water, and are produced in unbelievable amounts. (earthday.org)
I always end up finding some ridiculously cute things for unbelievable prices. (thefashionablehousewife.com)