What is security? From Webster's College Dictionary: security, n. 1. the state or quality of being secure; freedom from fear or danger 2. defense or protection 3. something given to secure the fulfillment of a contract; pledge 4. one who becomes surety for another 5. pl. stock certificates or bonds secure, adj. 1. free from fear, worry 2. free from danger; safe 3. firm, stable, or dependable