the GNU version of the Collaborative International Dictionary of English
n. A hydrous oxide of iron (HFeO2), occurring in prismatic crystals, also massive, with a fibrous, reniform, or stalactitic structure. The color varies from yellowish to blackish brown.
The Century Dictionary and Cyclopedia
n. Same as goethite.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a red or yellow or brown mineral; an oxide of iron that is a common constituent of rust