channer

noun3

1. •
   A user of other imageboard sites similar to 4chan.
2. •
   (Internet) A user of the imageboard site 4chan; a 4channer.

   • This is just one of a number of so-called 'false flag' operations undertaken by 'channers' in an effort to infiltrate and undermine progressive social movements. — 2016
3. •
   A flat fragment of sandstone, slate, etc. found in soil.