forever

UK: /fəˈrɛvə^r/ US: /fɔrˈɛvɚ, fər-/ ,(fôr ev′ər, fər-)

WordReference Random House Learner's Dictionary of American English © 2025

for•ev•er /fɔrˈɛvɚ, fər-/   adv. 

1. without ending;
   for all time;
   eternally:
   She's gone forever.
2. continually;
   incessantly;
   always:
   [often: be + ~ + verb-ing] He is forever complaining.

n. [uncountable]

3. a seemingly endless period of time:
   Don't spend forever on the phone.

WordReference Random House Unabridged Dictionary of American English © 2025

for•ev•er  (fôr ev′ər, fər-), adv. 

1. without ever ending;
   eternally:
   to last forever.
2. continually;
   incessantly;
   always:
   He's forever complaining.
3. Idioms forever and a day, eternally;
   always:
   They pledged to love each other forever and a day.

n. 

4. an endless or seemingly endless period of time:
   It took them forever to make up their minds.

• origin, originally phrase for ever 1660–70

Collins Concise English Dictionary © HarperCollins Publishers::

forever / fɔːˈrɛvə fə-/ adverb

1. Also: for ever without end; everlastingly; eternally
2. at all times; incessantly
3. for a very long time: he went on speaking forever

noun

1. (as object) a very long time: it took him forever to reply

USAGE
Forever and for ever can both be used to say that something is without end. For all other meanings, forever is the preferred form