The term "Nice Nelly" refers to a person who is overly modest or prudish. It was first used in 1925. Today's crossword included ENDMOST for "Bringing up the rear." The word dates from the 11th century and means "situated at the very end." Why does the word even exist? Why did anyone in the 11th century feel the need to take the word "end" and add the superfluous word "most" to it? As for the definition, how is "the very end" any different from "the end"?
I'm reminded of the story of a teenager who tried to cut in line outside a movie theater. A man said, "Hey, go to the end of the line!" The boy replied, "I can't---there's already somebody there."