Seeming doubtful or questionable; not clearly true or reliable; causing suspicion.
彼の説明はどこか疑わしいので、もう一度確認した。
His explanation seemed somewhat doubtful, so I checked again.
その証言には矛盾が多く、疑わしいと判断された。
The testimony had many contradictions and was judged to be suspicious.
セールの広告が疑わしいと思ったら、レビューを見てから買うといい。
If you think a sale advertisement is dubious, it's best to check reviews before buying.