Meaning of “realize” - Learner’s Dictionary

realize

verb [ T ] ( also UK -ise) uk us /ˈrɪəlaɪz/
NOTICE

B1 to notice or understand something that you did not notice or understand before:

[ + question word ] I didn't realize how unhappy she was.
I suddenly realized I'd met him before.
[ + (that) ] Some people just don't seem to realize that the world has changed.
realize an ambition/dream/goal, etc

to achieve something that you have wanted for a long time:

He had realized all his ambitions by the age of 30.
SELL

to sell things that you own:

to realize your assets
MAKE MONEY

to be sold for a particular amount of money:

The shares realized £1.4 million.

(Definition of “realize” from the Cambridge Learner’s Dictionary © Cambridge University Press)