複ふく々ふく線せんふくふくせんFreq.FrequencyTop 100,000Meanings1nounfour-track rail line; quadruple trackRailway term for a line with four tracks, typically two in each direction, allowing express and local services to run separately.この区く間かんは複ふく々ふく線せん化かされて、快かい速そくと各かく駅えき停てい