Silly exploit precipitated by Basil? (7-7)
I believe the answer is:
feather brained
'silly' is the definition.
(I've seen this before)
'exploit precipitated by basil?' is the wordplay.
'exploit' becomes 'feat' (synonyms).
'precipitated' becomes 'rained' (raining is a kind of precipitating).
'by' is a charade indicator (letters next to each other).
'basil?' becomes 'herb' (basil is an example).
'rained' put after 'herb' is 'herbrained'.
'feat'+'herbrained'='FEATHER-BRAINED'
(Other definitions for feather brained that I've seen before include "Scatty" , "one whose grey matter is down?" , "not sage?" , "Daft" , "Silly" .)