bitter end

/ˌbɪdər ɛnd/

Other forms: bitter ends

Definitions of bitter end

1. noun

   (nautical) the inboard end of a line or cable especially the end that is wound around a bitt
   type of:

   end, terminal

   either extremity of something that has length
2. noun

   the final extremity (however unpleasant it may be)
   “he was determined to fight to the bitter end”

   type of:

   extremity

   an extreme condition or state (especially of adversity or disease)