Unfurl (6)
I believe the answer is:
unroll
'unfurl' is the definition.
(I know that unfurl can be written as unroll)
This is all the clue.
(Other definitions for unroll that I've seen before include "Unfurl" , "Reverse winding or twisting" , "Open out (eg, scroll)" , "Dismantle the joint, perhaps" , "Gradually reveal" .)