Someone who is pertinacious continues trying to do something difficult rather than giving up quickly.
英漢詞典釋義
adj.
堅持的;固執的;堅決的
a pertinacious illness痼疾pertinacious bigotry固執的偏見
英英詞典釋義
Adjective
1. stubbornly unyielding;
"dogged persistence""dour determination""the most vocal and pertinacious of all the critics""a mind not gifted to discover truth but tenacious to hold it"- T.S.Eliot"men tenacious of opinion"