(1):
(a.) Acquired, as diseases; accidental.
(2):
(a.) Out of the proper or usual place; as, adventitious buds or roots.
(3):
(a.) Accidentally or sparingly spontaneous in a country or district; not fully naturalized; adventive; - applied to foreign plants.
(4):
(a.) Added extrinsically; not essentially inherent; accidental or causal; additional; supervenient; foreign.