adverb / adjective
midway
mid-WAY/ˌmɪdˈweɪ/
At or near the middle point between two places or stages.
The marker stands midway across the bridge.

Etymology
The pieces originally describe the middle of a path or distance. Used adverbially, they locate something halfway along a journey—or, figuratively, between stages of progress.
In context
equator is located midway between the north and the south pole.