er·ro·ne·ous 
(ĭ-rōnē-əs)
(ĭ-rōnē-əs)adj.
Containing or derived from error; mistaken: erroneous conclusions.
[Middle English, from Latin errōneus, from errō, errōn-, a vagabond, from errāre, to err, wander; see ers- in the Appendix of Indo-European roots.]
er·rone·ous·ly adv.
er·rone·ous·ness n.