The Grand Lexicon of Astronology is the principal post-disquisitional segment of the Omnidoxy within the Appendix of the Omnidoxy as part of the Original Omnidoxical Series solely authored and organised by Cometan and published by the Astronist Institution. The Grand Lexicon makes up the largest portion of the Appendix of the Omnidoxy at over 300,000 words and is considered the first dictionary of not only Astronism itself, but the entire Astronic tradition and culture, as studied by the astronology discipline.
 
The Grand Lexicon includes terms across the entire Astronic tradition regarding both Millettarian and Astronist philosophies and cultures. Its authority is further solidified through its categorised as part of the Omnidoxy and demonstrates its importance to the founding of Astronism and acts as a great expander of the elements surrounding the religion. Although there will be many more dictionaries concerning Astronism and astronology with greater comprehensiveness of the entirety of these vast subjects, The Grand Lexicon of Astronology will remain the progenitor for all of these.