1.  suspicious;  dubious;  questionable;  dodgy;  shady;  fishy
2.  doubtful;  unsure;  uncertain;  unlikely;  implausible
3.  untrustworthy;  unreliable;  clumsy;  awkward;  shaky;  poor
5.  ominous (e.g. weather);  threatening;  dangerous (e.g. financial situation);  uncertain
6.  suspicious (of a potential amorous relation)
7.  mysterious;  bewitching;  alluring;  enticing;  enchanting
also 妖しい