The Collaborative International Dictionary of English v.0.48:

Reliability \Re*li`a*bil"i*ty\ (r?-l?`?-b?l"?-t?), n.
   The state or quality of being reliable; reliableness.
   [1913 Webster]

WordNet (r) 3.0 (2006):

reliability
    n 1: the quality of being dependable or reliable [syn:
         dependability, dependableness, reliability,
         reliableness] [ant: undependability,
         undependableness, unreliability, unreliableness]

The Free On-line Dictionary of Computing (19 January 2023):

reliability

    An attribute of any system that consistently produces
   the same results, preferably meeting or exceeding its
   specifications.  The term may be qualified, e.g software
   reliability, reliable communication.

   Reliability is one component of RAS.

   (2000-08-13)