- (of a task, problem, etc.) Thorny; difficult to deal with, especially due to being complex or tricky.
"Be careful what you say to him; he's a nettlesome fellow."
- (of a person, thing, situation, etc.) Causing irritation, annoyance, or discomfort; bothersome, irksome.
"My poison ivy rash is very nettlesome."
"The task of proving Fermat’s “last” theorem remains nettlesome."