Menurut referensi berikut, 'dead space/area' mempunyai tiga pengertian:
1. daerah luar jangkauan tembak/pengamatan
2. daerah luar jangkauan sinyal radio
3. daerah luar jangkauan mekanik/elektronik
Untuk merangkum ketiga pengertian tsb, maka saya usulkan

dead space/area = daerah luar jangkauan

Kutipan & referensi:
DEAD SPACE:
1. AN AREA WITHIN THE MAXIMUM RANGE OF WEAPON, RADAR, OR OBSERVER, WHICH CANNOT BE COVERED BY FIRE OR OBSERVATION FROM A PARTICULAR POSITION BECAUSE OF INTERVENING OBSTACLES, THE NATURE OF THE GROUND, OR THE CHARACTERISTICS OF
THE TRAJECTORY, OR THE LIMITATIONS OF THE POINTING CAPABILITIES OF THE WEAPONS. 2. AN AREA OR ZONE WHICH IS WITHIN RANGE OF RADIO TRANSMITTER, BUT IN WHICH A SIGNAL IS NOT RECEIVED. 3. THE
VOLUME OF SPACE ABOVE & AROUND A GUN OR GUIDED MSL SYSTEM INTO WHICH IT CANNOT FIRE BECAUSE OF MECHANICAL OR ELECTRONIC LIMITATIONS