What it means

1. adjective located or originating from above
   “an overhead crossing”
2. noun a hard return hitting the tennis ball above your head
3. noun (nautical) the top surface of an enclosed space on a ship
4. noun a transparency for use with an overhead projector
5. noun (computer science) the disk space required for information that is not data but is used for location and timing
6. noun the expense of maintaining property (e.g., paying property taxes and utilities and insurance)
7. noun (computer science) the processing time required by a device prior to the execution of a command
8. adverb above the head
   “bring the legs together overhead”
9. adverb above your head
   “planes were flying overhead”