eternity
US /ɪˈtɝː.nə.t̬i/
UK /ɪˈtɝː.nə.t̬i/

1.
infinite or unending time
:
•
The universe stretches into eternity.
•
They swore to love each other for eternity.
2.
a period of time that seems to last forever, especially because it is boring or unpleasant
:
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Waiting for the results felt like an eternity.
•
The lecture dragged on for what seemed like an eternity.