spiral · noun C /ˈspɑɪ.rəl/
a downward spiral
C2 a situation which is getting worse very quickly, and which is difficult to control
Dictionary example:
After his death, the family went into a downward spiral.
Learner example:
Unemployment is one of the major problems of our society. It is the first step of a downward spiral. (Certificate of Proficiency in English; C2; German)