From Middle English diligent, from Old French diligent, from Latin diligens (“careful, attentive, diligent”), present participle of diligere (“to love, esteem much, literally to choose, select”), from di-, dis- (“apart”) + legere (“to choose”); see elect and select.
- Performing with intense concentration, focus, responsible regard.
- See also Wikisaurus:industrious
Related terms 
- diligent in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
- diligent in The Century Dictionary, The Century Co., New York, 1911
- third-person plural future active indicative of dīligō