laboriously (adv.)

• ardently
• arduously
• assiduously
• diligently
• energetically
• fervently
• hard
• hardly
• indefatigably
• industriously
• manfully
• onerously
• painfully
• relentlessly
• sedulously
• strenuously
• tirelessly
• unsparingly
• vehemently
• zealously