Sentence:  When Churchill and Roosevelt were considering their declaration of the Atlantic Charter, it was Attlee, acting with a <WSD>celerity</WSD> and a clarity of purpose that belied his reputation for caution, who insisted on including “freedom from want” as one of its aims, making economic rights and, with them, a decent life for all, one of the official aims of the war. 
Meaning of the word marked with <WSD> tags:  Speed, swiftness.