An adjective describing someone who is eager, earnest, and diligent—not casual or halfhearted but seriously committed. All three NT uses come from 2 Corinthians 8, where Paul describes Titus and another brother's earnest concern for the Corinthians and their giving (8:17, 22 twice). The word carries overtones of speed and energy ('in haste') but primarily denotes moral seriousness and zeal. Classical Greek uses it of good citizens, skilled craftsmen, and virtuous individuals—those who excel because they care deeply and act accordingly.