Compounds of 遺憾

• 遺憾
  (adj-na,n) regrettable
  unsatisfactory
  (P)
• 遺憾なく
  (adv) unobjectionally
  fully
• 遺憾千万
  (adj-na) highly regrettable
  utterly deplorable
• 遺憾無く
  (adv) unobjectionally
  fully
• 遺憾に堪えない
  (exp,adj-i) really regrettable