n (uncountable) capacity | Capacity of mind, especially to understand principles, truths, facts or meanings, acquire knowledge, and apply it to practice; the ability to learn and comprehend.
n (uncountable) information | Information, usually secret, about the enemy or about hostile activity|activities.
n (countable) A political or military department, agency or unit designed to gather information, usually secret, about the enemy or about hostile activity|activities.