A machine-gun nest is a military term that refers to a fortified position or structure built to protect an emplaced machine gun. It is a defensive structure that usually comprises a gun pit, sandbags, and other materials that can serve as a cover. However, there are several synonyms for machine-gun nest which include foxhole, bunker, pillbox, fortress, redoubt, and stronghold. These words describe similar structures, but they may differ in their size, shape, and level of fortification. These synonyms may be useful in communication to clarify the type of structure that is being referred to in a military context.