A kedion is a particle that can interfere with electronic processes.

Kedions can prevent the correct operation of transporters. (TNG novel: Genesis Force)

A kedion pulse can interfere with Data's ethical subroutines. In 2370, Jean-Luc Picard and Geordi La Forge used a phased kedion pulse to bring Data's program online after it was disabled by Lore. (TNG episode: "Descent, Part II")