Main Entry: ad·ven·ti·tious

Pronunciation: \ˌad-(ˌ)ven-ˈti-shəs, -vən-\

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 <adventitious roots>

— ad·ven·ti·tious·ly adverb