Definitions

1. adjective

Having a reddish-brown or rusty color, especially in reference to fungi or lichens.

“The rubiginous patches on the old tree were a sign of its age.”

2. adjective

Covered or discolored with a reddish-brown or rusty substance, especially fungi or lichens.

“The stone was covered in rubiginous growth, which indicated it had been exposed to the elements for too long.”