Rejected. It sounds so... personal, but don't take it that way.
When your e-filed return comes back as rejected, it just means that the government has sent your return back to you for correction.
Sometimes a rejection can be a blessing in disguise. For example, if you got another W-2 in the mail right after you e-filed and your return was rejected, you can simply add the W-2 to your return before you resubmit it, instead of dealing with the hassle of amending an accepted return.