noun
amphibious assault ship
A military vessel designed to deploy and support ground forces during amphibious operations.
アメリカ海軍の強襲揚陸艦は、海兵隊の上陸作戦を支援する。
The U.S. Navy's amphibious assault ships support Marine Corps landing operations.
揚陸艦 is a broader term for any landing ship, while 強襲揚陸艦 specifically refers to an assault ship with enhanced capabilities for direct attack support.
Compound of 強襲 (assault) + 揚陸 (landing) + 艦 (warship). A modern military term, likely a calque from English 'amphibious assault ship'.