noun

• (chiefly in the plural) Materials of war: armaments, weapons and ammunition.
  "Just as we can say that an English girl who leaves the narrow circle of her old life, and goes into a munition factory and joins a union and takes part in its debates, will never after be a docile home-slave; so we can say that the clergyman who helps in Y. M. C. A. work in France, or in Red Cross organization in America, will be less the bigot and formalist forever after."
• (chiefly in the plural, military, NATO) Bombs, rockets, missiles (complete explosive devices, in contrast to e.g. guns).
• (rare, obsolete) A tower or fortification.
  "I wil stand vpon my watch, and fixe my steppe vpon the munition: and I wil behold, to see what may be sayd to me, and what I may answer to him that rebuketh me."

verb

• (transitive) To supply with munitions.
  "Why was I there, munitioning, blacklegging, slaving as though my bread depended on it?"