Definition of adventitious in US English:



  • 1Happening or carried on according to chance rather than design or inherent nature.

    ‘my adventures were always adventitious, always thrust on me’
    • ‘The influence a writer can exert is purely adventitious.’
    • ‘Light was excluded during this stage to prevent adventitious photodamage.’
    • ‘For his closest friends and family his demise was shockingly adventitious.’
    • ‘Then, as if in tribute to the adventitious nature of idea generation, the solution came to him in his sleep.’
    • ‘Nowhere was this adventitious attitude to life more evident than in the rural music scene.’
    • ‘But that specification will be partly adventitious.’
    • ‘They are adventitious benefits, which for policy reasons are not to be regarded as diminishing the plaintiff's loss.’
    • ‘Not unnaturally, he basks in adventitious glory.’
    • ‘Opportunities for adventitious habitat creation have been widely accepted.’
    • ‘It is by no means adventitious that this statement combines an ethical proposition with an economic prescription.’
    • ‘That result was not an adventitious distortion of the tradition.’
    • ‘It does not feel, subjectively, like some interfering, adventitious stuff has been removed.’
    • ‘So far, the connection has been very adventitious.’
    • ‘What the audience identify with are the apparently adventitious features imposed by the logic of the form itself.’
    • ‘It was an adventitious consequence of the fixing of the date of the hearing.’
    • ‘All of creation is an adventitious assault and modification of this preexisting ‘condition.’’
    • ‘So we are not dealing with a case of purely adventitious conversion to Christianity.’
    • ‘The narrative perhaps shares with a good many other such accounts the adventitious quality of a just so story.’
    • ‘It was strange how you can run into people in such an adventitious way.’
    • ‘Gouges in the sides may be adventitious consequences of the casting process, but in this context they read as scars.’
    unplanned, unpremeditated, accidental, unintentional, unintended, unexpected, unforeseen, involuntary, chance, fortuitous, serendipitous, coincidental, casual, random, fluky, unlooked-for, unhoped-for, not bargained for, out of the blue, without warning
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    1. 1.1 Coming from outside; not native.
      ‘the adventitious population’
      • ‘No adventitious spooks are required to account for this-the ‘laws’ of biochemistry and physics are spooky enough.’
      • ‘One possible source for this high frequency dispersion could be trace amounts of adventitious oxygen or contributions from iron.’
      • ‘Indeed, it has been proposed that these adventitious materials play a role in in meso crystallization.’
      • ‘After all, we have dealt with adventitious GM presence in maize previously on several occasions.’
      foreign, alien, non-native, outside, external, extraneous, extrinsic
      View synonyms
    2. 1.2Biology Formed accidentally or in an unusual anatomical position.
      ‘propagation of sour cherries by adventitious shoots’
      • ‘Asymmetrical patches of growing feathers were considered adventitious replacement and not scored as molt.’
      • ‘Flight-feather molt categories were symmetric, adventitious, and juvenal.’
      • ‘In adventitious embryony, the embryo develops directly from nucellar or chalazal tissue without an intervening gametophyte stage.’
      • ‘Although both mutants were isolated, each is morphologically distinct, suggesting adventitious genetic alterations.’
      • ‘It has previously been shown that adventitious organogenesis and embryogenesis could occur in parallel from in vitro-cultured tissues of Helianthus.’
    3. 1.3Botany (of a root) growing directly from the stem or other upper part of a plant.
      • ‘Oxygen transport from shoot through adventitious roots has been visualized directly.’
      • ‘The young parasite then develops a tubercle, with adventitious roots and a shoot.’
      • ‘If adventitious rooting could be introduced into a crop like cotton, it could lead to new production efficiencies.’
      • ‘The total number of primary adventitious roots per plant was closely correlated with corm dry weight.’
      • ‘After removal, such stem segments could produce adventitious roots under moist soil conditions, and produce new plants.’
      • ‘Plants were washed carefully out of soil and the individual adventitious roots originating from the stem base were removed for testing.’


Early 17th century: from Latin adventicius ‘coming to us from abroad’ (from advenire ‘arrive’) + -ous (see also -itious).