Noun
(military) The areas between a weapon and its target in which the trajectory is not greater than the typical height of a human (about 1.8 meters)
(military) The area or space around the target of a missile in which it has a probability of landing or exploding
(medicine) A region of the neck bounded by the skull base, alar fascia and prevertebral fascia, from which an infection can spread directly to the thorax.
Source: en.wiktionary.org