Pilum

Definition: The pilum was the Roman legionary's six foot javelin, which he hurled at the enemy at the start of the engagement before he used the sword. The wooden shaft on he pilum was a yard long, fitted with a yard long iron head with a barbed point. The Roman leader Marius altered construction of the pilum so if the head stuck in the enemy's shield, he would be unable to pull it out to re-use it.