In volume one, under the heading "generation" the following definition is given;
"A Generation commonly refers to all persons who were born about the same time."
Since the publication of this tome, Jesus has "evidently" changed the meaning of "generation". So, should this entry in "Insight of the Scriptures" be rejected as "old light"?
See also "Which Truth is "the Truth"? and Question for Jehovah's Witnesses: Do You Own a Dictionary?