noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A technique for blocking spam (junk e-mail) by configuring a non-existent server as the primary MX record, so that initial contact always fails. A legitimate sender is likely to try the next server, which should succeed. Internet, uncountable

Etymology

From no + list + -ing.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.