Define: adventitious

From the January 23rd, 2010 edition of The Spectator, in an article by Jacob Heilbrunn, Meet the Fantastic Mr. Fox.

The martial imagery is not adventitious.

From Merriam-Webster.com

Main Entry: ad ven ti tious
Pronunciation: \ˌad-(ˌ)ven-ˈti-shəs, -ven-\
Function: adjective
Etymology: Latin adventicius
Date: 1603
1 : coming from another source and not inherent or innate {a Federal house without adventitious later additions}
2 : arising or occurring sporadically or in other than the usual location

- ad ven ti tious ly adverb