Sentence:  "'Fair Enslaver!'" cried Mr. Enderby. "You must know 'Fair Enslaver:' there is not a sweeter <WSD>catch</WSD> than that. Come, Miss Ibbotson, begin; your sister will follow, and I&mdash;"/ But it so happened that Miss Ibbotson had never heard 'Fair Enslaver.' 
Meaning of the word marked with <WSD> tags:  A fragment of music or poetry. (s)