noun
bunker; covered trench; dugout
Military term for a protective shelter, often underground or covered, used for defense or protection from enemy fire.
兵士たちは掩蔽壕に身を隠した。
The soldiers hid in the bunker.
トーチカ is a loanword from Russian, referring specifically to a concrete pillbox or small fortified emplacement, while 掩蔽壕 is a broader term for any covered defensive trench or dugout.
塹壕 is a general term for a trench, often open, while 掩蔽壕 specifically implies a covered or protected trench or bunker.
Compound of 掩蔽 (えんぺい, 'cover, conceal') and 壕 (ごう, 'trench, dugout'). The exact historical derivation is uncertain, but the term is a modern military coinage.