The document discusses vocabulary development and techniques for providing expanded definitions of words. It defines expanded definition as explaining the meaning of a word or phrase by distinguishing its characteristics, providing extra facts and examples, and what cannot be included. Some techniques for expanded definitions include etymology, history, description, examples, and comparisons/contrasts. The document then provides an expanded definition of the word "Earth" as an example, discussing its etymology, characteristics, and history as the third planet from the sun inhabited by humans.