Sentence:  Meanwhile my friend had not ceased to worry about me. His love for me led him to think that, if I persisted in my objections to meat-eating, I should not only develop a weak constitution, but should remain a duffer, because I should never feel at home in English society. When he came to know that I had begun to interest myself in books on vegetarianism, he was afraid lest these studies should muddle my head; that I should <WSD>fritter</WSD> my life <WSD>away</WSD> in experiments, forgetting my own work, and become a crank. 
Meaning of the word marked with <WSD> tags:  To decrease in an incremental way without hindrance.