подозри́тельно
adverb
as a predicative
it is suspicious
suspiciously; suspiciously, with suspicion
вести́ себя́ подозри́тельно
behave suspiciously
смотре́ть подозри́тельно
look suspiciously; look with suspicion
на ACC
at something
askance (of look: with disapproval)
queerly, questionably, fishily