n. - A military guardhouse, bunker (normally above ground or dug into a fixed position with 360-degree or nearly 360-degree visibility) or other structure from which observation can take place and, under most
circumstances, weapons can be fired as a means of defense or security.
*Loosely (possibly incorrectly, this is opinion-based)
associated with the term "pillbox" due to its
similarity with typical pill boxes, which are used for storing medication, are often translucent (for visibility), and can be opened at will.