Many glossaries of wildland fire terms exist. Most are extensive (many terms) rather than intensive (much information about each term). For example, the 1996 NWCG Glossary of Wildland Fire Terminology contains more than 1500 terms, but each is limited to 255 characters (about 20 words). Unfortunately, the complex terminology of wildland fire science does not lend itself to brief definitions. Other glossaries have been produced to meet the needs of individual organizations, publications, projects or sub-sets of wildland fire terminology. Systems for Environmental Management and the Missoula Fire Sciences Lab are collaborating in the development of FireWords, an expert-authored, annotated, illustrated glossary of fire science terminology. We strive for a more intensive though less extensive glossary than now exists. We are limiting the glossary to terms related to the science of wildland fire (fire behavior, fire effects, fire chemistry, fuels, fire modeling, etc.); terms related solely to policy or management are not be included except as necessary to support technical terms. Rather than limit definition length, FireWords encourages annotation and illustration as needed to fully explain a term. FireWords is an expandable, electronic glossary with related terms hyper-linked together. It can be used to look up the definition of a specific term, or to browse the terms of a specific discipline within wildland fire science. We created a single glossary file for normal use on the user's local computer, but serve the same content served over the Internet for occasional use when the glossary is not available locally. We do not envision distributing a printed document; instead, users will print only the definitions they need. End users can suggest terms to include in future updates.We have created an initial version of FireWords containing approximately 200 terms. Groups of related terms have been authored by noted specialists in the field. We then compiled and and edited the definitions for consistency. We expect FireWords to be a growing document, much like the Fire Effects Information System.