labienus Share definition Flag A professional Roman soldier in the late Roman Republic, one of Julius Caesar's lieutenants. Labienus, despite being helpful to Caesar during the Gallic Wars, was beaned by Caesar's forces in the Battle of Munda. labienus by Et tu, Brute? November 20, 2017 0 0 Get merch Get the labienus mug. Buy Now — $32.95 See more merch