ship of the line
Historical term for a large warship used in line-of-battle tactics during the age of sail.
戦列艦は18世紀の海戦で主力となった。
Ships of the line were the main force in 18th-century naval battles.
Compound of 戦列 (battle line) + 艦 (warship), a calque from English 'ship of the line' or similar European naval terminology.