Related Clues:

• Immeasurable period
• Loooong wait
• Astronomical periods
• See 41-Down
• Gets on in years
• Forever, seemingly
• Many a moon
• Ripens
• Entries in a family album
• Clock watcher's wait, seemingly
• Endless years
• A lo-o-ong time
• Two or more eras
• Sentence units
• Very long stretch