The Collaborative International Dictionary
Maroon lake
Maroon \Ma*roon"\ (m[.a]*r[=oo]n"), a. [F. marron chestnut-colored, fr. marron a large French chestnut, It. marrone; cf. LGr. ma`raon. Cf. Marron.] Having the color called maroon. See 4th Maroon.
Maroon lake, lake prepared from madder, and distinguished for its transparency and the depth and durability of its color.
Wiktionary
maroon lake
n. A lake pigment prepared from madder, distinguished for its transparency and the depth and durability of its colour.