What is the meaning of difficulty?

noun

• An effort that is inconvenient.
  • usage: "I went to a lot of trouble"; "he won without any trouble"; "had difficulty walking"; "finished the test only with great difficulty"
  • synonyms: trouble
• A factor causing trouble in achieving a positive result or tending to produce a negative result.
  • usage: "serious difficulties were encountered in obtaining a pure reagent"
• A condition or state of affairs almost beyond one's ability to deal with and requiring great effort to bear or overcome.
  • usage: "grappling with financial difficulties"
• The quality of being difficult.
  • usage: "they agreed about the difficulty of the climb"
  • synonyms: difficultness