invalidity Meaning, Definition & Usage

  1. noun illogicality as a consequence of having a conclusion that does not follow from the premisses
    invalidness.

WordNet

In`va*lid"i*ty noun
Etymology
Cf. F. invalidité, LL. invaliditas want of health.
Definitions
  1. Want of validity or cogency; want of legal force or efficacy; invalidness; as, the invalidity of an agreement or of a will.
  2. Want of health; infirmity. Obs. Sir W. Temple.

Webster 1913