IPA: //ʌnɪkˈsɛld//
KK: /ʌnɪkˈsɛld/
Being better than all others in a particular area or quality.
Her performance in the competition was unexcelled, earning her the top prize.
Unexcelled → It is formed from "un-" (meaning not) and "excel" (from Latin "excellere", meaning to rise or be elevated). The word means not being surpassed or having no equal in quality or performance.
Think of 'not' ('un-') being able to 'rise above' ('excel') — that's why unexcelled means something that cannot be surpassed.