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Security

se·cu·ri·ty
n. pl. se·cu·ri·ties

1. Freedom from risk or danger; safety.
2. Freedom from doubt, anxiety, or fear; confidence.
3. Something that gives or assures safety, as: a. A group or department of private guards: Call building security if a visitor acts suspicious. b. Measures adopted by a government to prevent espionage, sabotage, or attack. c. Measures adopted, as by a business or homeowner, to prevent a crime such as burglary or assault: Security was lax at the firm's smaller plant. d. Measures adopted to prevent escape: Security in the prison is very tight.
4. Something deposited or given as assurance of the fulfillment of an obligation; a pledge.
5. One who undertakes to fulfill the obligation of another; a surety.
6. A document indicating ownership or creditorship; a stock certificate or bond.