To work hard over a period of time, often with persistence or effort.

लगातार मेहनत करना

English Usage: She has to grind away at her studies if she wants to pass the exam.

Hindi Usage: अगर वह परीक्षा में पास होना चाहती है तो उसे अपनी पढ़ाई पर लगातार मेहनत करनी होगी।