On Usenet, the process of posting a new message that replaces a previous one. Most clients won't let you do this unless they believe that you are the person that wrote the original, in order to reduce abuse. However, it is fairly trivial to forge a supersede header.

Fascinatingly, by far the most common error in creating a forged supersede is to spell it supercede.

Superseding a message is effectively equivalent to posting a cancel followed by a new message, but is accomplished in a single message. Like cancels, many servers do not honour supersedes due to large-scale abuse.

Su`per*sede" (?), v. t. [imp. & p. p. Superseded (?); p. pr. & vb. n. Superseding.] [L. supersedere, supersessum, to sit above, be superior to, forbear, omit; super above + sedere to sit: cf. F. supers'eder. See Sit, and cf. Surcease.]

1.

To come, or be placed, in the room of; to replace.

2.

To displace, or set aside, and put another in place of; as, to supersede an officer.

3.

To make void, inefficacious, or useless, by superior power, or by coming in the place of; to set aside; to render unnecessary; to suspend; to stay.

Nothing is supposed that can supersede the known laws of natural motion. Bentley.

4. OldLaw

To omit; to forbear.

 

© Webster 1913.