Eternity
Definition 1 of 3
Pro Tip 1/2
Exaggerated Duration
Used to express a feeling that time is moving very slowly or waiting has been too long. The last five minutes of the exam dragged on for an eternity.
Pro Tip 2/2
Hyperbolic Speech
Often used to overstate a situation for emotional effect, not to be taken literally. I haven't seen you in an eternity!