from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Not inherent but added extrinsically. See Synonyms at accidental.
  • adj. Biology Of or belonging to a structure that develops in an unusual place: adventitious roots.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. From an external source; not innate or inherent, foreign.
  • adj. Accidental, additional, appearing casually.
  • adj. Not congenital; acquired.
  • adj. Developing in an unusual place or from an unusual source.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Added extrinsically; not essentially inherent; accidental or causal; additional; supervenient; foreign.
  • adj. Out of the proper or usual place.
  • adj. Accidentally or sparingly spontaneous in a country or district; not fully naturalized; adventive; -- applied to foreign plants.
  • adj. Acquired, as diseases; accidental.

from The Century Dictionary and Cyclopedia

  • Added extrinsically; not springing from the essence of the subject, but from another source; foreign; accidentally or casually acquired: applied to that which does not properly belong to a subject, but which is superadded or adopted, as in a picture or other work of art, to give it additional power or effect.
  • In botany and zoology, appearing casually, or in an abnormal or unusual position or place; occurring as a straggler or away from its natural position or habitation; adventive.
  • In anatomy, of the nature of adventitia: as, the adventitious coat of an artery.
  • In phytogeography, naturalized from a distant formation: opposed to *vicine. A term proposed by Pound and Clements. Compare adventitious, 2.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. associated by chance and not an integral part


From Latin adventīcius, foreign, from adventus, arrival; see advent.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin adventicius ("foreign"), from adveniō ("arrive"). (Wiktionary)


  • Cuttings are plant pieces, usually stems or branches, capable of growing new roots, called adventitious roots.

    5. How plants live and grow

  • Leaf-buds occasionally arise from the roots, when they are called adventitious; this occurs in many fruit trees, poplars, elms and others.

    Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1

  • But as it was occasionally inexpedient to carry about measuring-chains a boy would do well to know the precise length of his own foot-pace, so that when he was deprived of what Hurree Chunder called adventitious aids 'he might still tread his distances.


  • But as it was occasionally inexpedient to carry about measuring-chains a boy would do well to know the precise length of his own foot-pace, so that when he was deprived of what Hurree Chunder called adventitious aids’ he might still tread his distances.


  • If Barnes once called the contest "posh bingo", this year looks a lot less adventitious.

    The Man Booker judges seem to find reading a bit hard | Catherine Bennett

  • Third, probably very few of the participants (other than perhaps adventitious semi-professional looters) expected to gain anything in terms of significant personal profit or meaningful social betterment as a consequence of the upheavals in Los Angeles.

    Matthew Yglesias » Endgame

  • Things he did, no matter how adventitious or spontaneous, struck the popular imagination as remarkable.

    Chapter XI

  • In one of David Attenborough's 'The Private Life Of Plants' episodes, he talks on similar fallen trunks that eventually give rise to a row of other daughter 'trees' growing out of the main trunk; these eventually grow adventitious roots and become independent.

    An undead tree

  • As Meeker sees comedy as having a biological rather than idealistic focus, so Baillie sees it as properly centering on the “original distinctions of nature” rather than on the “adventitious distinctions ... of age, fortune, rank, profession, and country” (13).

    Joanna Baillie’s Ecotopian Comedies

  • The skilled reader is not dependent on the adventitious aids of easiness or brightness; he is no longer, for instance, dependent upon plot for his enjoyment of fiction, or upon what is called 'actuality' or 'incident', or mere verisimilitude of description.

    2010 January 08 | NIGEL BEALE NOTA BENE BOOKS


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  • From p. 104 of F. Scott Fitzgerald's The Great Gatsby: "Someone with a positive manner, perhaps a detective, used the expression'madman' as he bent over Wilson's body that afternoon, and the adventitious authority of his voice set the key for the newspaper reports next morning."

    September 29, 2012

  • JM is relaxed about adventitious adventures.

    June 13, 2010

  • Totally madeupical.

    February 25, 2008

  • For some reason, this always sounds madeupical to me. :-)

    February 24, 2008

  • See calcareous for a usage note.

    February 23, 2008