IPA: /ˌoʊvərəˈtʃivər/
KK: /oʊvərəˈtʃivər/
A person who performs better or achieves more than what is expected, often excelling in academics or other areas at a young age.
As an overachiever, she always strives to get the highest grades in her class.
Overachiever → It is formed from "over-" (meaning excessively or beyond) and "achiever" (from the verb "achieve", which comes from Old French *achever*, meaning to complete or bring to a conclusion). The word "overachiever" describes someone who achieves more than what is expected or required, often excessively so.
Think of someone who goes 'beyond' ('over-') what is expected in their accomplishments — that's why an overachiever is someone who achieves more than the norm.