further forward in space or time than somebody/something; in front of somebody/something
Example:
- Two boys were ahead of us.
- Ahead of us lay ten days of intensive training.
earlier than somebody/something
Example:
- I finished several days ahead of the deadline.
further advanced than somebody/something; in front of somebody, for example in a race or competition
Example:
- She was always well ahead of the rest of the class.
- His ideas were way ahead of their time (= very new and so not widely understood or accepted).