IPA: /ˌʌn.sərˈpɑːst/
KK: /ʌnˈsɜrˌpæst/
Better than anything else; having no equal or rival.
Her talent in painting is unsurpassed by anyone in the competition.
Unsurpassed → It is formed from "un-" (meaning not) and "surpass" (from Old French *surpasser*, meaning to exceed or go beyond). The word "unsurpassed" means not exceeded or not gone beyond in quality or achievement.
Think of 'not' ('un-') being able to 'exceed' ('surpass') something — that's why unsurpassed means something that cannot be exceeded.