Definition of ab initio in English:

ab initio

adverb

Law
formal
  • From the beginning.

    ‘the agreement should be declared void ab initio’
    • ‘Enormous as the difference undoubtedly is between these faculties in the two cases, the difference is conceded not to be one existing ab initio.’
    from the beginning, from the start, initially, originally, from first principles, to begin with, to start with, primarily
    da capo
    from scratch, from the word go
    from the beginning, from the start, initially, originally, from first principles, to begin with, to start with, primarily
    da capo
    from scratch, from the word go
    View synonyms

adjective

Law
formal
  • [attributive] Starting from the beginning.

    ‘he was instructing ab initio pilots’

Origin

Latin.

Pronunciation:

ab initio

/ˌab ɪˈnɪʃɪəʊ/