assiduousness

English

Etymology

assiduous +‎ -ness

Noun

assiduousness (uncountable)

1. Conscientious and unremitting diligence.
   • 1856, William L. G. Smith, The Life and Times of Lewis Cass‎, p. 323:

     Finding that his health was failing, because of the assiduousness which a proper discharge of the duties of the position demanded the year round, he acquainted the President with his desire to withdraw from public duties.