* Exclude: This is the most common and direct opposite. It means to leave something out or keep something from being part of a group.
* Omit: This means to leave something out, similar to exclude.
* Reject: This implies refusing to accept something.
* Disregard: This means to ignore something.
* Leave out: This is a more informal way of saying exclude.
The best word to use will depend on the specific situation and what you want to emphasize.