an effort that is inconvenient
"I went to a lot of trouble"
"he won without any trouble"
"had difficulty walking"
"finished the test only with great difficulty"
a factor causing trouble in achieving a positive result or tending to produce a negative result
"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
"grappling with financial difficulties"
the quality of being difficult
"they agreed about the difficulty of the climb"
The state of being difficult, or hard to do.
"The new software update introduced a significant difficulty in syncing files across devices."
In plain English: Difficulty is when something is hard to do or understand.
"The difficulty of climbing that steep hill made everyone want to sit down and rest."
Usage: Use "difficulty" to describe the state of something being hard to accomplish or understand. It functions as an uncountable noun when referring to trouble in general, though you can add a number before it only when specifying distinct problems.
The word "difficulty" comes from Middle English and Latin, where it originally meant something hard to do or achieve. It entered English via French, carrying forward its sense of hardship derived from combining roots meaning "not easy."