Source : Webster's Revised Unabridged Dictionary (1913)

Light-armed \Light"-armed`\ (-[aum]rmd`), a.
   Armed with light weapons or accouterments.

Source : WordNet®

light-armed
     adj 1: armed with light weapons [syn: {lightly-armed}]
     2: armed with light equipment and weapons; "a light-armed
        brigade"