Backscatter (e-mail)
WordNet
verb
(1) Scatter (radiation) by the atoms of the medium through which it passes
WiktionaryText
Noun
- The deflection of particles and/or radiation by nuclear and/or electromagnetic forces through angles greater than 90 degrees to the original direction of travel.
- The particles and/or radiation deflected in this manner.
- A portion of the energy or a laser that is scattered back in the seeker's direction by an obscurant.