noun
L-shaped gutter; L-shaped drain
A drainage channel with an L-shaped cross-section, commonly used in civil engineering and construction.
道路の側溝にはＬ字溝がよく使われている。
L-shaped gutters are often used for roadside ditches.
Ｕ字溝 is a U-shaped gutter, while Ｌ字溝 has an L-shaped cross-section.
From the shape of the letter L (エル) and 字 (じ, 'character') plus 溝 (こう, 'gutter/drain').