safety

n. (pl. -ies)
1 the condition of being safe; freedom from danger or risks.
2 (attrib.) a designating any of various devices for preventing injury from machinery (safety bar; safety lock). b designating items of protective clothing (safety helmet).
Phrases and idioms:
safety-belt
1 = seat-belt.
2 a belt or strap securing a person to prevent injury. safety-catch a contrivance for locking a gun-trigger or preventing the accidental operation of machinery. safety curtain a fireproof curtain that can be lowered to cut off the auditorium in a theatre from the stage.
safety factor (or factor of safety)
1 the ratio of a material's strength to an expected strain.
2 a margin of security against risks. safety film a cinematographic film on a slow-burning or non-flammable base. safety first a motto advising caution.
safety fuse
1 a fuse (see FUSE(2)) containing a slow-burning composition for firing detonators from a distance.
2 Electr. a protective fuse (see FUSE(1)). safety glass glass that will not splinter when broken. safety harness a system of belts or restraints to hold a person to prevent falling or injury. safety lamp a miner's lamp so protected as not to ignite firedamp. safety match a match igniting only on a specially prepared surface. safety net a net placed to catch an acrobat etc. in case of a fall. safety pin a pin with a point that is bent back to the head and is held in a guard when closed. safety razor a razor with a guard to reduce the risk of cutting the skin.
safety-valve
1 (in a steam boiler) a valve opening automatically to relieve excessive pressure.
2 a means of giving harmless vent to excitement etc. safety zone US an area of a road marked off for pedestrians etc. to wait safely.
Etymology: ME sauvete f. OF sauveteacute f. med.L salvitas -tatis f. L salvus (as SAFE)