1
general::
Phrase(s): off-the-cuff
Fig. spontaneous; without preparation or rehearsal. • Her remarks were off-the-cuff, but very sensible. • I’m not very good at making speeches off-the-cuff.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Impromptu, extemporaneous, as in His speech was entirely off the cuff. This term suppposedly alludes to the practice of speakers making last-minute notes on the cuff of a shirtsleeve. [1930s]
American Heritage Idioms