Often sensible about future, say (5)
I believe the answer is:
tense
'future say' is the definition.
(future tense)
'often sensible about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'TENSE' can be found hidden inside 'often sensible'.
(Other definitions for tense that I've seen before include "Maybe future" , "Uneasy" , "Anxious - future, perhaps?" , "present, perhaps?" , "Subject to strain" .)