noun, counter
Refers to a single stroke in writing a kanji character. Also used as a counter for the number of strokes in a kanji.
この漢字は画数が多い。
This kanji has many strokes.
「永」という字は五画です。
The character '永' has five strokes.
The kanji 画 originally depicted a boundary or division, later extended to mean a mark or stroke. The reading かく is the on'yomi.