Synset
the quality of being difficult to do
<noun.attribute>
hardness
ruggedness
sample sentences
"he assigned a series of problems of increasing hardness"
"the ruggedness of his exams caused half the class to fail"
lexical pointers
derivationally related form
hard
hard
lexical pointers
derivationally related form
rugged
semantic pointers
hypernym
difficulty, difficultness