bitter_end
1. [ noun ] the final extremity (however unpleasant it may be)
Examples:

"he was determined to fight to the bitter end"

Related terms: extremity
2. [ noun ] (nautical) the inboard end of a line or cable especially the end that is wound around a bitt
Related terms: end line seafaring
Similar spelling:   bittern
  Bitterman
  bitternut
  Biederman
  bitterness