Heroism without support? Absolutely (4)
I believe the answer is:
Here is my best explanation:
'absolutely' is the definition.
'heroism without support?' is the subsidiary indication.
'heroism' becomes 'bravery' (I've seen this before).
'without' is a deletion indicator.
'support?' becomes 'bra' (a support for the breasts).
'bravery' with 'bra' removed is 'very'.
(Other definitions for very that I've seen before include "- light is a flare", "Frightfully", "In a high degree; actual", "To a large extent", "Actual; in a high degree", "light, perhaps", "To a high degree or extent", "Really", "jolly British!" and "Truly".)