IPA: /ˈʃaɪniər/
KK: /ˈʃaɪniər/
Having a surface that reflects light; brighter than something else.
The new car is shinier than the old one.
Comparative: shinier
Superlative: shiniest
Shinier is formed from "shine" (from Old English "scīnan", meaning to emit light or be bright) and "-ier" (a comparative suffix indicating more). The word "shinier" means more bright or reflecting more light than something else.
Think of something that emits light or is bright ('shine') and remember that 'shinier' means it reflects more light than another object.