ardently, arduously, assiduously, bec et ongles, burdensomely, difficultly, diligently, effortfully, energetically, fervently, hammer and tongs, hard, hardly, heart and soul, indefatigably, industriously, manfully, onerously, operosely, painfully, relentlessly, sedulously, strenuously, the hard way, tirelessly, toilsomely, tooth and nail, unsparingly, vehemently, with a will, with difficulty, with effort, with much ado, zealously