What does "overhead" mean?

Overhead: Aloft; above; in or attached to the ceiling or roof; in the story or upon the floor above; in the zenith. While overhead the moon Sits arbitress. Milton. Note: Also used adjectively; as, an overhead crane, gear, etc. Overhead engine, a vertical steam engine in which the cylinder stands above the crank. -- Overhead work, a general term in manufactories for countershafting and gearing, when overhead.