Definition of "adventive" [ad•ven•tive]

• Not native to and not fully established in a new habitat or environment; locally or temporarily naturalized: an adventive weed. (adjective)
• An adventive organism. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Unto the first of these, the considerations of the original of the soul, whether it be native or adventive, and how far it is exempted from laws of matter, and of the immortality thereof, and many other points, do appertain: which have been not more laboriously inquired than variously reported; so as the travail therein taken seemeth to have been rather in a maze than in"
• "It appeareth likewise that I have assigned to summary philosophy the common principles and axioms which are promiscuous and indifferent to several sciences; I have assigned unto it likewise the inquiry touching the operation or the relative and adventive characters of essences, as quantity, similitude, diversity, possibility, and the rest, with this distinction and provision; that they be handled as they have efficacy in nature, and not logically."
• "It is really from the union of Hellenism, in its breadth, its sanity of purpose, its calm possession of beauty, with the adventive, the intensified individualism, the passionate colour of the romantic spirit, that springs the art of the nineteenth century in England, as from the marriage of Faust and Helen of Troy sprang the beautiful boy Euphorion."