Definition of unicity in English:

unicity

noun

rare
  • 1[mass noun] The fact of being or consisting of one, or of being united as a whole:

    ‘the presbyterial and episcopal service is not humanly viable unless by rediscovering the unicity of the priesthood’
    1. 1.1 The fact or quality of being unique:
      ‘Aqina's novel doctrine of the unicity of forms’
      • ‘This is a general phenomenon in the whole secularist press: instead of a thorough analysis and a lively debate worthy of the importance and unicity of the report, the page is turned as quickly as possible.’
      • ‘This is not merely a question of terminology, but above all of respecting a basic truth of the Catholic faith: that of the unicity [unique nature] of the Church of Jesus Christ.’

Pronunciation:

unicity

/juːˈnɪsɪti/