WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
taxing to the utmost; testing powers of endurance
adjective.
characterized by or performed with much energy or force
Word Usage
"Davutoglu spoke at length about what he described as strenuous efforts by Turkey and Brazil to meet the terms of a letter Obama sent to Erdogan and Brazil's president, outlining the terms of the deal to fuel a research reactor."