The Unified Astronomy Thesaurus (UAT) will be an open, interoperable and community-supported thesaurus that unifies the existing Astronomy & Astrophysics thesauri into a single, freely-available open thesaurus for astronomical objects and concepts. Because astronomy and astrophysics are fast-moving fields (terms such as ‘exoplanets’ and 'dark energy' were relatively unknown 10 years ago), the poster will also describe the ways that the UAT will leverage expertise from astronomers, physicists and librarians to keep the thesaurus both current and accurate. One of the primary drivers behind the creation of the UAT is the wish to support semantic enrichment of astronomy literature and databases. We anticipate it will be used as a common language across publishers and platforms, to connect articles and data sets. We also hope this unified vocabulary will inspire a new range of cross-silo data sharing. The UAT began as a collaboration between the American Institute of Physics (AIP) and Institute of Physics (IOP), which donated their collection astronomy of terms to the AAS. SPIE has also donated their astronomy terms towards the effort. Our plans include providing a community-supported mechanism for reviewing, discussing, and evaluating the continuous evolution of terminology in astronomy and astrophysics.