noun
roadbed; subgrade
Civil engineering term for the prepared foundation layer of a road or railway, below the surface course.
新しい道路の路盤工事が始まった。
Construction of the roadbed for the new road has begun.
counter
lines on a Go board; board size
Used as a counter to specify the number of lines on a Go board, e.g. 9路盤 means a 9×9 board. Domain-specific Go terminology.
初心者は9路盤で囲碁を学ぶことが多い。
Beginners often learn Go on a 9×9 board.