Search Result for "arduousness": 
Wordnet 3.0

NOUN (1)

1. extreme effortfulness;
[syn: arduousness, strenuousness]


The Collaborative International Dictionary of English v.0.48:

Arduousness \Ar"du*ous*ness\, n. The quality of being arduous; difficulty of execution. [1913 Webster]
WordNet (r) 3.0 (2006):

arduousness n 1: extreme effortfulness [syn: arduousness, strenuousness]