SPURIOUS

lacking authenticity or validity

false

counterfeit

plausible but false
SYN - specious
"spurious inferences"

born out of wedlock
SYN - bastardly
ANT - true
"The dominions of both rules passed away to their spurious or doubtful offspring."

intended to decieve
SNY - inauthentic
"a spurious work of art."

"He had grown sick of the spurious conversations he would have with these so-called friends."

"He wasn't interested in spurious people such as this, he only wanted real, raw humans."

"He knew a spurious dollar bill when he saw one, and this one - with scooby-doo instead of George Washington was surely counterfeit."