Electronic warfare undertaken to prevent or reduce an enemy's effective use of the electromagnetic spectrum(noun)
WordNet. Princeton University. 2010.
Use "electronic countermeasures" in a sentence
"M.jor James M. Bartsch Electronic Warfare Trophy, for the B-52 unit compiling the most points in electronic countermeasures activity, went to the 319th Bomb Wing, Grand Forks AFB, North Dakota."
"Bartsch Trophy, B-52 unit with most points in all electronic countermeasures activity, 410th Bomb Wing."
"Meyer Trophy, top FB-111 unit compiling most points in low - level bombing and electronic countermeasures activity, terrain following, and low-time control, 509th Bomb Wing"