Security - (noun)
(1) A financial instrument that shows ownership, evidence of a debt, and a right to the share in the earnings of the issuer - for example bonds and shares. (2) Protection against assault, damage, and theft. (3) Job security refers to how much assurance the employee has that they will keep their job.
Source: Adapted from Business Dictionary
Example of Use: (1) You can buy and sell securities on the financial markets. (2) The company installed heavy security around the headquarters after hearing about threats to their staff and property. (3) Workers on permanent contracts have better job security than workers on fixed-term contracts.