Difficult problem
Hole and difficult problem are semantically related. In some cases you can use "Hole" instead a noun phrase "Difficult problem".
Hole
Hole noun - A place in a surface allowing passage into or through a thing.
Difficult problem and hole are semantically related. You can use "Difficult problem" instead a noun "Hole".
Mutual synonyms
Cite this Source
Hole and Difficult problem. (2016). Retrieved 2026, July 22, from https://thesaurus.plus/related/difficult_problem/hole
Difficult problem & Hole. N.p., 2016. Web. 22 Jul. 2026. <https://thesaurus.plus/related/difficult_problem/hole>.
Hole or Difficult problem. 2016. Accessed July 22, 2026. https://thesaurus.plus/related/difficult_problem/hole.
Google Ngram Viewer shows how "difficult problem" and "hole" have occurred on timeline