dubiously

adjective

1. causing doubt; ambiguous; vague: a dubious remark
2. feeling doubt; hesitating; skeptical
3. with the outcome undecided or hanging in the balance: dubious battle
4. rousing suspicion; questionable; shady: a dubious character

Origin: L dubiosus, doubtful < dubius, doubting, uncertain < du- < or akin to duo, two + IE base *bhu-, *bheu-, to be