Improvising when adjusting a big blind (2-7)
I believe the answer is:
ad-libbing
'improvising' is the definition.
(I've seen this before)
'adjusting a big blind' is the wordplay.
'adjusting' is an anagram indicator.
'a'+'big'+'blind'='abigblind'
'abigblind' anagrammed gives 'AD-LIBBING'.
'when' is the link.
(Other definitions for ad-libbing that I've seen before include "Speaking without preparation" , "Improvising" .)