Where is the last word in Y section of dictionary?

This is a bit of a trick question! Dictionaries don't typically organize words by their last letter. They are organized alphabetically, so the last word in the "Y" section would be the last word in the entire dictionary.

The answer to that is impossible to definitively say! Dictionaries are constantly being updated with new words. However, you can say that the last word in the "Y" section is the word that comes alphabetically closest to the very last word in the dictionary.