Talk without notes; improvise (2-3)
I believe the answer is:
ad-lib
This clue is a double definition.
'talk without notes' is the first definition.
(I've seen this before)
'improvise' is the second definition.
(I know that improvise can be written as ad-lib)
(Other definitions for ad-lib that I've seen before include "Extemporise" , "Spontaneously" , "Improvise" , "freely" , "Unprepared remark" .)