dtgk 16across

[devadiva]

is the answer armoire? Large cabinet that oncce would have held weapons

[prospector]

yes -

Wearing "armor" (protective clothing, often made from metal) that you keep in an "armoire" (closet) protects you from an "armer" (someone handling weapons)

[rbind]

I wondered if it might be armoury because the clue "was large cabinet that would have been used to store WEAPONS".