An indefinite and very long period of time, often a time period of a billion years in geology or astronomy.

A long period of time; an age.

एक लंबा समय

English Usage: She felt as if an eon had passed since they last met.

Hindi Usage: उसे ऐसा लग रहा था जैसे वे आखिरी बार मिले थे तब से एक लंबा समय बीत गया हो।