Adventitious is a formal adjective that signifies something originating from an external source, rather than being inherent or innate. In botany, it specifically refers to structures that develop sporadically or in unusual locations. For example, new shoots can grow from the roots of creosote bushes, forming separate plants. Similarly, adventitious roots can appear on a tomato plant stem where roots are not typically found. This meaning emphasizes something arising outside of the usual pattern or expected place. Jane Eyre's Mr. Rochester possesses qualities that are either intrinsic, meaning innate, or adventitious, meaning acquired. The word entered English in the early 17th century from the Latin adventīcius. Its primary meaning has remained "coming from outside; external, foreign." By the late 17th century, its botanical sense emerged, describing irregular or misplaced growth. This dual meaning allows it to describe both external influences and unusual occurrences.