ADVENTITIOUS, coming from outside, in no sense part of the substance or circumstance (Lat. adventicius, coming from abroad). Carlyle called a man's clothes, or condition of life "adventitious wrappages," as being superadded and not a natural part of him. In botany the word means that which is not normal to the plant, e.g., buds or roots out of place, or strange spots and streaks not native to the flower.