A "blue cloud" is a dangerous area effect resulting from rapid, sustained utterances of profanity. Those in the area of effect experience either anxiety or elation depending on their idiosyncracies. Often encountered at truck stops or in the homes of desperate housewives. See also "turn the air blue".
If this therapist dislikes profanity, it won't work for us, because there'll be a blue cloud of profanity in the room.
by Baalorian August 29, 2015