diligent

Từ điển American Heritage Dictionary 4th

dil·i·gent (dĭlʹə-jənt)adj.
Marked by persevering, painstaking effort. See Synonyms at busy. [Middle English, from Old French, from Latin dīligēns, dīligent- present participle of dīligere, to esteem, love : dī-, dis-, apart; see dis- + legere, to choose; See leg- in Indo-European Roots.] dilʹi·gent·ly adv.