expression, godan verb (-ku)
paint red; miniate
Literally 'to draw/paint with red'. 'Miniate' is a rare English term for painting in red, especially in manuscripts. In modern Japanese, this expression is not common; it may appear in artistic or historical contexts.
中世の写本では、重要な箇所を朱で描くことがあった。
In medieval manuscripts, important passages were sometimes painted in red.
Compound of 朱 (あか, 'red, vermilion') + で (instrumental particle) + 描く (えがく, 'to draw, paint'). The reading あか for 朱 is a native Japanese word, while しゅ is the Sino-Japanese reading.