Fucus

·noun A paint; a dye; also, false show.

II. Fucus ·noun A genus of tough, leathery seaweeds, usually of a dull brownish green color; rockweed.

fucus
† fūcus, i, m., = φῦκος, I rock-lichen , orchil , used as a red dye for woollen goods, Lichen rocce...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
fucus
fūcus (1) ī, m , φῦκος, rock-lichen, orchil (a red dye for woollen goods); hence, a dye-stuff, red ...

An Elementary Latin Dictionary