What is "leves"

Leves (Singular: Levis) were javelin-armed skirmishers in the army of the early Roman republic. They were typically some of the youngest and poorest men in the legion, and could not afford much equipment. They were usually outfitted with just a number of light javelins and no other equipment. There were 300 leves in a legion, and unlike other infantry types they did not form their own units, but were assigned to units of hastati — heavier sword-armed troops. Their primary purpose on the battlefield was to harass the enemy with javelin fire and support the heavy infantry who fought in hand-to-hand combat. Accensi and rorarii were also light missile troops and had similar roles.