The term 'billions' can be defined in a variety of ways. The crossword solutions for this term include the words Sagan (5 letters), TONS (4 letters), EONS (4 letters), LOTS (4 letters), COSMIC (6 letters), GATES (5 letters), and ADAM (4 letters). Sagan refers to the late astronomer Carl Sagan, who was known for his popular science books and television series. TONS is a unit of measurement for mass, and EONS is a very long period of time. LOTS is another word for a large amount, and COSMIC refers to the universe or outer space. GATES is a reference to Bill GATES, the founder of Microsoft, and ADAM is a biblical reference to the first man created by God. All of these words refer to the concept of billions in different ways.