Today it means: Generally a screen or embankment to protect the rear of a position from enemy attack, from bomb splinters from behind, from enemy fire from a commanding height, or fire from flanking positions. In common English usage since World War II, the term "parados", particularly in trench warfare, has largely been discarded in favour of "rear parapet", which, etymologically speaking, is a contradiction in terms. In some contexts the term "rear traverse" is preferred, but no usage is exclusive. Full definition →
Borrowed from French parados; in turn the French derived from Italian para, defence, cognate with English parry, plus French dos cognate with Latin dorsum: the back, i.e. the dorsal aspect. Parados is unrelated to parodos either in etymology or in meaning.
Etymology from Wiktionary, CC BY-SA 4.0.