diligently, actively, energetically, strenuously, eagerly, earnestly, seriously, intently, determinedly, rapidly, dexterously, industriously, assiduously, sedulously, carefully, steadily, laboriously, painstakingly, unremittingly, studiously, perseveringly, hurriedly, briskly, vivaciously, animatedly, purposefully, ardently, arduously, fervently, spiritedly, nimbly, zealously, agilely, vigorously, drudgingly, indefatigably, restlessly, vigilantly, enthusiastically, speedily, hastily, persistently, expeditiously, unweariedly, with all dispatch, like hell, like the dickens, like the devil*.

Antonyms listlessly, idly, perfunctorily.