Meaning of “purpose” - Learner’s Dictionary

purpose

noun uk us /ˈpɜːpəs/
REASON [ C ]

B1 why you do something or why something exists:

The main purpose of the meeting is to discuss the future of the company.
The drug may be legalized for medical purposes.
INTENTION [ U ]

the feeling of knowing what you want to do:

He seems to have lost all sense of purpose.
on purpose

B1 intentionally:

I didn't do it on purpose, it was an accident.
serve a purpose

to have a use:

These small village shops serve a very useful purpose.
→ See also cross purposes , to/for all intents (and purposes)

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