Minuscule coals were blown about (5,4)
I believe the answer is:
lower case
'minuscule' is the definition.
(I've seen this before)
'coals were blown about' is the wordplay.
'blown about' is an anagram indicator (I've seen this in other clues).
'coals'+'were'='coalswere'
'coalswere' with letters rearranged gives 'LOWER-CASE'.
(Other definitions for lower case that I've seen before include "lacking capital" , "Small letters" , "Small, UNLIKE THIS!" , "What a baggage-handler might do" , "in which I may never appear" .)