Compounds of 空しく

• 空しく
  (adv) in vain
  to no purpose
  fruitlessly
• 空しくなる
  (v5r) to die
  to expire
• 健闘空しく
  (exp) fighting in vain
• 努力も空しく
  (n) after efforts in vain
• 空しく日を送る
  (exp) to spend days in vain
• 空しく費やされた時
  (n) wasted time
  time passed in vain
• 宝の山に入りながら手を空しくして帰る
  (exp,v5r) though sitting on a pile of riches, one comes back empty handed
  to have a good opportunity only to let it slip from your grasp