lane. 1. 'lane'. A lane is a narrow road which can be used by vehicles, especially in the country. A lane is also a part of a main road which is marked by the edge of the road and painted line, or by two painted lines.The lorry was travelling at 20mph in the slow lane.. 'lane'. A lane is a narrow road which can be used by vehicles, especially in the country. A lane is also a part of a main road which is marked by the edge of the road and painted line, or by two painted lines. The lorry was travelling at 20mph in the slow lane.