noun

• (uncountable) The condition of not being threatened, especially physically, psychologically, emotionally, or financially.
• (countable) Something that secures.
• An organization or department responsible for providing security by enforcing laws, rules, and regulations as well as maintaining order.
• (law) Something that secures the fulfillment of an obligation or law.
• (law) Freedom from apprehension.
• (finance, often in the plural) A tradeable financial asset, such as a share of stock.ᵂ
• (finance) Proof of ownership of stocks, bonds or other investment instruments.
• (finance) Property etc. temporarily relinquished to guarantee repayment of a loan.
• A guarantee.
• (obsolete) Carelessness; negligence.