- The Pilum appears to be named for the pilum, a throwing spear carried by Roman legionnaires.
The Pilum used a fire-and-forget guidance system and was fitted with a replicator system for reloading. Between 2407 and 2411 it had been upgraded and could select between anti-tank and fragmentation loads. (Bait and Switch: "Brother on Brother, Daughter on Mother")
In 2411 Lieutenant Rachel Connor used a Pilum launcher in an attack on a Borg installation in the Delta Quadrant, killing a large assimilated Gorn and several tactical drones with anti-tank rounds, before being informed of the frag option by Petty Officer Jose Luiz. (Bait and Switch: "Brother on Brother, Daughter on Mother")