1. The scientific study of the history, symbolism, and usage of flags or; by extension, any general listing of flags: Jacob's history professor and mentor, Mr. Dean, was intrigued by his proposal to do more extensive research in the field of vexillology.
2. The scholarly study of the history, symbolism, etiquette, design, manufacture, and other aspects of standards: Vexillology can include a wide variety of fields that apply to flags and their uses.
3. Etymology: from Latin vexillum, a term used by the Romans to refer to a kind of standard with a fabric hung from a horizontal crossbar on a pole. It is the closest equivalent in the classical languages to what we call a flag today.

In his book, Dr. Smith says, "While the use of flags goes back to the earliest days of human civilization, the study of that usage in a serious fashion is so recent that the term for it (vexillology, coined by the author of this book) did not appear in print until 1959. This has resulted in a lack of uniformity in flag terms and, worse still, a lack of source material concerning actual usage on which standardization might be based."

A Few Examples of the Flag Terms Used in Vexillology