also: こ
prefix
Prefix used with color terms to indicate a dark shade. The reading こ appears in a few set compounds like 濃グレー, but のう is more common.
See also: 濃グレー (のうグレー)
濃グレーのスーツを着て会議に出席した。
He attended the meeting wearing a dark gray suit.
この絵の具は濃い青色だ。
This paint is a dark blue.
prefix
Only with reading のう
Prefix indicating high concentration or thickness, used in technical or descriptive compounds. Restricted to the reading のう.
濃硫酸は取り扱いに注意が必要だ。
Concentrated sulfuric acid requires careful handling.
このスープは濃厚な味わいだ。
This soup has a thick, rich flavor.
Antonym prefix meaning 'light' or 'dilute', as in 薄グレー (light gray) or 薄味 (light flavor).
From the kanji 濃, which carries meanings of 'thick', 'dense', and 'dark'. The reading のう is the on'yomi, while こ is a rare alternative on'yomi used in a few compounds.