Vaijyanti of Yadavparakash (10-14 century) गणाध्याय gives some interesting synonyms for the word गण. It generally means multitude/flock. It also means number. High numbers are called महागण.
I couldn't restrain my brain bugs to find phonetic similarity between these synonyms & words used for ancient oligarchical Indian republics (गण/गणराज्य/गणसङ्घ). It is possible that few of these words might become synonyms later due to their use in relation to गण।
Most interesting synonym is व्रात. A derived term Vratya is a term associated with almost all Gaṇas. This term is frequently used for deviation from absolute rules. Some Gaṇas were called Vratshatropjivin.
Next synonym is व्रज. Names of Gaṇas near Magadha Vajji, Lichchvis, Shakya and Mallas can be associated with synonym व्रज, Lichchvi with a high number लक्ष and Shakya from high number शंख/शंकु & Malla from मल्ल (son of Vratya).
व्रज is also origin of region name ब्रज near Mathura. वृन्दावन can be associated with synonym बृन्द, which is also a high number.
जात & जटा are also synonyms (gender neutral) of गण. in these words, we can trace origin of present caste name of Jat people, who are a close match to old north-western Ganas in terms of location/behaviour.
*typos and gramos. Ignore plz.