Sentence:  He was a <WSD>plump</WSD> little man and we had been walking uphill at a pace—set by him—far too rapid for his short legs. He breathed stertorously, and half the drops which glimmered on his rotund face were not rain but sweat. 
Meaning of the word marked with <WSD> tags:  Having a full and rounded shape; chubby, somewhat overweight.