Synonyms for specious

modified

specious applies to that which is superficially reasonable, valid, etc. but is actually not so, and it connotes intention to deceive a specious excuse; plausible applies to that which at first glance appears to be true, reasonable, valid, etc. but which may or may not be so, although there is no connotation of deliberate deception a plausible argument; credible is used of that which is believable because it is supported by evidence, sound logic, etc. a credible account