The idiom "Once in a blue moon" is used to describe an event that occurs very infrequently. To choose the correct meaning, let's analyze the options:
Based on the analysis, the correct meaning of the idiom "Once in a blue moon" is Rarely.
The CEO's sudden resignation threw the board into a tailspin.
What does the idiom "threw into a tailspin" mean?
The politician's vague answers clearly showed he was just beating around the bush.
What does "beating around the bush" imply?