Synonyms of the word

fail-safe

• adj. That does not cause undue damage in the event of failure.
• n. A fail-safe device or mechanism.
• v. To compensate automatically, in the event of a failure.

mechanism

• n. (within a machine or machinery) any mechanical means for the conversion or control of motion, or the transmission…
• n. Any combination of cams, gears, links, belts, chains and logical mechanical elements.
• n. A group of objects or parts that interact together. (as in Political machine).
• n. A mental, physical, or chemical process.
• n. (philosophy) The theory that all natural phenomena can be explained by physical causes.

safe

• adj. Not in danger; free from harm's reach.
• adj. Free from risk; harmless, riskless.
• adj. Providing protection from danger; providing shelter.
• adj. (baseball) When a batter successfully reaches first base, or when a baserunner successfully advances to…
• adj. Properly secured; secure.
• adj. (used after a noun, often forming a compound) Not susceptible to a specified source of harm.
• adj. (Britain, slang) Great, cool, awesome, respectable; a term of approbation.
• adj. (slang) Lenient, usually describing a teacher that is easy-going.
• adj. Reliable.
• adj. Cautious.
• n. A box, usually made of metal, in which valuables can be locked for safekeeping.
• n. (slang) A condom.
• n. (dated) A ventilated or refrigerated chest or closet for securing provisions from noxious animals or insects.
• v. (transitive) To make something safe.

secure

• adj. Free from attack or danger; protected.
• adj. Free from the danger of theft; safe.
• adj. Free from the risk of eavesdropping, interception or discovery; secret.
• adj. Free from anxiety or doubt; unafraid.
• adj. Firm and not likely to fail; stable.
• adj. Free from the risk of financial loss; reliable.
• adj. Confident in opinion; not entertaining, or not having reason to entertain, doubt; certain; sure; commonly…
• adj. Overconfident; incautious; careless.
• v. To make safe; to relieve from apprehensions of, or exposure to, danger; to guard; to protect.
• v. To put beyond hazard of losing or of not receiving; to make certain; to assure; frequently with against…
• v. To make fast; to close or confine effectually; to render incapable of getting loose or escaping.
• v. To get possession of; to make oneself secure of; to acquire certainly.