Meaning of “effort” - Learner’s Dictionary

effort

noun uk us /ˈefət/
ATTEMPT [ C, U ]

B1 an attempt to do something:

[ + to do sth ] We huddled together in an effort to keep warm.
He was making an effort to be sociable.
ENERGY [ U ]

B1 the energy that you need to do something:

I put a lot of effort into organizing the party.
[ + to do sth ] It would take too much effort to tidy my bedroom.

[ U ] the force that is used to make something move

be an effort

to be difficult or painful:

After his accident, walking was an effort.

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