Related Clues:

• Old animated heroine Flux
• Long geological period (var.)
• Geologist's unit
• Many, many epochs
• It's a long time
• Geological timespan (Var.)
• Unit in a geology book
• Very long period
• Ages and ages (var.)
• Immense time span
• Forever and a day (Var.)
• Quite a long time (Var.)
• Length of a boring class, so it seems
• Billion years (var.)
• Long measure of time (Var.)