The Collaborative International Dictionary of English v.0.48:

Safety \Safe"ty\, n. [Cf. F. sauvet['e].]
   1. The condition or state of being safe; freedom from danger
      or hazard; exemption from hurt, injury, or loss.
      [1913 Webster]

            Up led by thee,
            Into the heaven I have presumed,
            An earthly guest . . . With like safety guided down,
            Return me to my native element.       --Milton.
      [1913 Webster]

   2. Freedom from whatever exposes one to danger or from
      liability to cause danger or harm; safeness; hence, the
      quality of making safe or secure, or of giving confidence,
      justifying trust, insuring against harm or loss, etc.
      [1913 Webster]

            Would there were any safety in thy sex,
            That I might put a thousand sorrows off,
            And credit thy repentance!            --Beau. & Fl.
      [1913 Webster]

   3. Preservation from escape; close custody.
      [1913 Webster]

            Imprison him, . . .
            Deliver him to safety; and return.    --Shak.
      [1913 Webster]

   4. (Amer. Football) the act or result of a ball-carrier on
      the offensive team being tackled behind his own goal line,
      or the downing of a ball behind the offensive team's own
      goal line when it had been carried or propelled behind
      that goal line by a player on the offensive tream; such a
      play causes a score of two points to be awarded to the
      defensive team; -- it is distinguished from touchback,
      when the ball is downed behind the goal after being
      propelled there or last touched by a player of the
      defending team. See Touchdown. Same as Safety
      touchdown, below.
      [Webster 1913 Suppl. +PJC]

   5. Short for Safety bicycle. [archaic]
      [Webster 1913 Suppl.]

   6. a switch on a firearm that locks the trigger and prevents
      the firearm from being discharged unintentionally; -- also
      called safety catch, safety lock, or lock. [archaic]
      [PJC]

WordNet (r) 3.0 (2006):

safety
    n 1: the state of being certain that adverse effects will not be
         caused by some agent under defined conditions; "insure the
         safety of the children"; "the reciprocal of safety is risk"
         [ant: danger]
    2: a safe place; "He ran to safety" [syn: safety, refuge]
    3: a device designed to prevent injury or accidents [syn:
       guard, safety, safety device]
    4: (baseball) the successful act of striking a baseball in such
       a way that the batter reaches base safely [syn: base hit,
       safety]
    5: contraceptive device consisting of a sheath of thin rubber or
       latex that is worn over the penis during intercourse [syn:
       condom, rubber, safety, safe, prophylactic]
    6: a score in American football; a player is tackled behind his
       own goal line

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "safety":
   aegis, arm guard, assurance, backstop, buffer, bulwark, bumper,
   contraceptive, copyright, cover, crash helmet, cushion, dashboard,
   defense, dodger, eye, face mask, fender, finger guard, foot guard,
   fuse, goggles, governor, guard, guardrail, hand guard, handrail,
   hard hat, helmet, impregnability, insulation, interlock,
   inviolability, invulnerability, knee guard, knuckle guard,
   laminated glass, lee, life preserver, lifeline,
   lightning conductor, lightning rod, mask, mudguard, nose guard,
   pad, padding, palladium, patent, pilot, preservation, preventive,
   prophylactic, protection, protective clothing, protective custody,
   protective umbrella, refuge, safeguard, safekeeping, safeness,
   safety glass, safety plug, safety rail, safety shoes,
   safety switch, safety valve, sanctuary, screen, seat belt,
   security, shade, shadow, shelter, shield, shin guard, sun helmet,
   umbrella, watchful eye, windscreen, windshield



The Free On-line Dictionary of Computing (30 December 2018):

safety

   See safe, safety-critical system.