His alarming behavior raised concerns among his friends.
unsettling feeling
Frequency:
60
%
There was an unsettling feeling in the air.
ominous signs
Frequency:
50
%
The dark clouds were ominous signs of an approaching storm.
Idiomatic Expressions for disquieting
Phrase: a disquieting atmosphere
Meaning: an atmosphere that is unsettling or disturbing
Usage: There was a disquieting atmosphere in the abandoned house.