Noun difficultness has 1 sense

• difficultness(n = noun.attribute) difficulty - the quality of being difficult; "they agreed about the difficulty of the climb"
has particulars: effortfulness, asperity, grimness, hardship, rigor, rigorousness, rigour, rigourousness, severeness, severity, hardness, ruggedness, formidability, toughness, burdensomeness, heaviness, onerousness, oppressiveness, niceness, subtlety, inconvenience, troublesomeness, worriment
is a kind of quality
Derived form adjective difficult₁