Ferruginous \Fer*ru"gi*nous\, a. [L. ferruginus, ferrugineus, fr. ferrugo, -ginis, iron rust: cf. F. ferrugineux. See Ferrugo.]

1. Partaking of iron; containing particles of iron. --Boyle.

2. Resembling iron rust in appearance or color; brownish red, or yellowish red.

Source: Webster's Revised Unabridged Dictionary (1913)