at a middle point in space or time between two things [= partway]
halfway through/up/down/between etc
He chased Kevin halfway up the stairs.
It was a terrible film - I left halfway through.
traffic queues stretching back halfway to London
the halfway stage/mark/point
They've just reached the halfway stage of the project.
to have done something that will allow you to achieve something else:
Establish the right relationships at work and you're halfway there.
to achieve something partly but not completely:
We're still only halfway to finishing the job.
reasonably good, normal, successful etc:
the only halfway decent hotel here