Assiduous means diligent, attentive or hardworking.
Assiduous is an adjective.
Synonyms: determined, constant, tenacious, persevering, diligent, earnest, hardworking, laborious, persistent.
Antonyms: lax, lazy, idle, casual, cavalier, indolent, undetermined.
Success in cricket requires assiduous devotion to the game.
The teachers agree that Rahul is the most assiduous student in the school.
The police conducted an assiduous search for the murder weapon.
Indolent work habits will get you nowhere; you must be assiduous if you want to be promoted in this institution.