MYR'MIDON, noun [Gr. a multitude of ants.] Primarily, the Myrmidons are said to have been a people on the borders of Thessaly, who accompanied Achilles to the war against Troy. Hence the name came to signify a soldier of a rough character, a desperate soldier or ruffian.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI