Droungos (Greek: δροῦγγος, sometimes δρόγγος, drongos) or drungus is a late Roman and Byzantine term for a battalion-sized military unit, and later for a local command guarding mountain districts.
It derives from Gaulish *dhrungho (see Old Irish drong; Old Breton drogn or drog), meaning "tribe", "group", "throng" or "crowd".
An alternative Germanic etymology (thrunga) cited by some historians,[1] originates in 17th-century guesswork which has been rejected by the overwhelming majority of philologists.
He is the first author to employ the cognate adverb droungisti (Greek: δρουγγιστί), with the sense of "in group formation" or "small-group tactics".
Thus each moira or droungos was the analogue of a modern regiment or brigade, initially circa 1000 men strong (and hence also referred to as a chiliarchia).