(idiomatic) Whose future is uncertain due to an anticipated threat or change in circumstance.
(idiomatic) Under suspicion; subject to critical inspection.
(idiomatic) In or into controversial circumstances.
Source: en.wiktionary.orgAfter leaving City Hall under a cloud, uniformed James preached reform two blocks east of Chandler's oil company offices, and was the talk of the town in 1929. Source: Internet
In both versions, Lex Luthor leaves Smallville "under a cloud of rumor and suspicion", when his father is mysteriously killed. Source: Internet
In 1934, Bill Woodfull led Australia back to England on a tour that had been under a cloud after the tempestuous cricket diplomacy of the previous bodyline series. Source: Internet
A bit of miscalculation and your reputation is under a cloud. Source: Internet
A letter written, the computer tidied up (some more) and a new voice recording toy taken out the box and examined before the cobwebs growing around it threaten to make it disappear altogether under a cloud of silken weave. Source: Internet
Seventeen-year-old Andrew Taylor, recently kicked out of boarding school in Connecticut under a cloud of shame, is sent off to an all boys school near London. Source: Internet