Position:
* Over: This is the most common opposite, referring to a position directly above something.
* Above: Similar to "over," but can also imply a higher position without being directly above.
* On: This signifies a position directly on top of something.
* Upon: Similar to "on," but can be more formal.
Other meanings:
* Over: This can also be used as the opposite of "under" when referring to a quantity (e.g., "under budget" vs. "over budget").
* Above: This can also be used as the opposite of "under" when referring to a level of quality (e.g., "under par" vs. "above par").
Example:
* "The book is under the table." Opposite: "The book is on the table."
* "The project is under budget." Opposite: "The project is over budget."
To determine the best opposite word, consider the specific context and the intended meaning.