Eternity/ɪˈtɜːrnəti/ Definition 1 of 3Pro Tip 1/2Exaggerated 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 2/2Hyperbolic Speech Often used to overstate a situation for emotional effect, not to be taken literally. I haven't seen you in an eternity!