Meaning: impromptu response; quick response with little thought (example 1, example 2)
Comment: There are two senses of this idiom. One is of the quick response to something, the "off the cuff remark."
Rewrite 1: off the sunbeam
Rewrite 2: out of the clouds
Rewrite 3: brain spark
Another is the seeming impromptu response that is actually the result of more cunning thinking, the "off the cuff quote."
Rewrite 4: off the palm (notes in your palm)
Rewrite 5: off the ceiling (figuring in your head and looking at the ceiling while calculating)
Rewrite 6: one-eye count (a facial expression assumed while calculating)
The recast depends more on the sense you're using. How would you rewrite it?
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