Definition of terminus a quo in US English:

terminus a quo

noun

  • 1The earliest possible date for something.

    • ‘In fact, the chapter's conclusion only states a terminus a quo with any conviction, while his earlier confidence regarding a terminus ante quem seems to disappear unexplainably.’
    • ‘We can establish a terminus a quo, the earliest possible date at which the book could have been finalized.’
    • ‘These may give a terminus a quo but will never give an airtight terminus ad quem unless you know that the manuscript is autograph; you may be sure that a poem or a letter was written in 1540, but it may have been transcribed in 1680.’
    • ‘If the terminus a quo does not lie within the decade A.D.70-80, it cannot well be pushed back earlier than A.D.95.’
    1. 1.1 A starting point or initial impulse.
      • ‘We are at the beginning of this school year - the terminus a quo.’
      • ‘The terminus a quo of the whole period is the issuing of a decree ‘to restore and to build Jerusalem.’’

Origin

Latin, literally ‘end from which’.

Pronunciation

terminus a quo

/ˌtərmənəs ä ˈkwō/