Showing great care and perseverance.

कठिन परिश्रमी

English Usage: She was assiduous in her studies, dedicating many hours to her homework.

Hindi Usage: वह अपनी पढ़ाई में कठिन परिश्रमी थी, अपने गृहकार्य के लिए कई घंटे समर्पित करके।