Unroll (6)
I believe the answer is:
unfurl
'unroll' is the definition.
(I know that unroll can be written as unfurl)
This is the entire clue.
(Other definitions for unfurl that I've seen before include "Open (e.g. brolly)" , "Allow (flag) to fly" , "Open (a rolled umbrella)" , "Open out like flag" , "Spread out as with flag" .)