单词：laborious 

形容词

• 
  [1.a.laborious] (同义词:[arduous( adj. 费劲的, 辛勤的, 险峻的 )]  [backbreaking( adj. 非常辛劳的 )]  [grueling( n. 重罚, 严惩 )]  [gruelling]  [hard( adj. 硬的, 坚固的, (问题, 工作等)困难的, 艰苦的, 猛烈的, 确实的 adv. 努力地, 辛苦地, 坚硬地, 牢固地, 接近地, 猛烈地 )]  [heavy( adj. 重的, 繁重的, 巨大的, 沉重的, 阴沉的 adv. 沉重地, 笨重地, 大量地 n. 重物, 严肃角色 )]  [laborious( adj. (指工作)艰苦的, 费力的, (指人)勤劳的 )]  [operose( adj. [古]费力的, 困难的, 辛勤的 )]  [punishing(adj.累人的 )]  [toilsome( adj. 辛苦的 )]  )
• 
  注释列句：characterized by effort to the point of exhaustion; especially physical effort; "worked their arduous way up the mining valley"; "a grueling campaign"; "hard labor"; "heavy work"; "heavy going"; "spent many laborious hours on the project"; "set a punishing pace"
• 近义词 -> [effortful( adj. 显示努力的,充满努力的,需要努力的 )] 
  派生词 -> [labor( n. 劳动, 努力, 工作, 劳工, 分娩, 阵痛 vi. 劳动, 努力争取(for), 苦干 vt. 详细分析, 麻烦 )]  [laboriousness]