also: け
noun
ruled line; rule
Refers to a printed or drawn line on paper, such as on ruled notebook paper or forms.
ノートの罫に沿って文字を書く。
Write letters along the ruled lines of the notebook.
noun
line on a game board
Specifically the grid lines on a go board, shogi board, or similar game boards.
碁盤の罫の交点に石を置く。
Place a stone on the intersection of the lines of the go board.
Obsolete kana reading; not used in modern Japanese.
Kana spelling is acceptable when the kanji is not needed, though the kanji is common.
The kanji 罫 is composed of 罒 (net) and 圭 (jewel), but the derivation is uncertain. It is used to represent ruled lines or grid lines.