Ad`ven*ti"tious (?), a. [L.
adventitius.] 1. Added extrinsically; not
essentially inherent; accidental or causal; additional; supervenient;
foreign.
To things of great dimensions, if we annex an
adventitious idea of terror, they become without comparison
greater.
Burke.
2. (Nat. Hist.) Out of the proper or usual
place; as, adventitious buds or roots.
3. (Bot.) Accidentally or sparingly
spontaneous in a country or district; not fully naturalized; adventive; --
applied to foreign plants.
4. (Med.) Acquired, as diseases;
accidental.
-- Ad`ven*ti"tious*ly, adv. --
Ad`ven*ti"tious*ness, n.