suspiciously

doubtingly, doubtfully, skeptically, dubiously, uncertainly, distrustfully, distrustingly, unbelievingly, questioningly, problematically, in doubt, in a doubtful manner, causing suspicion, encouraging suspicion, with caution, with reservation, with some reservation, not gullibly, not wholeheartedly, not without reservations, not without doubts, with a grain of salt, with a pinch of salt, cum grano salis (Latin), like a doubting Thomas*.