The woman starts to escape, running clear (5)
I believe the answer is:
sheer
'clear' is the definition.
(I've seen this before)
'the woman starts to escape running' is the wordplay.
'the woman' becomes 'she' (I've seen this before**).
'starts to' says to take the initial letters.
The initial letters of 'escape running' is 'er'.
'she'+'er'='SHEER'
(Other definitions for sheer that I've seen before include "Diaphanous, filmy" , "Plumb" , "Very steep or diaphanous" , "Unmitigated; perpendicular" , "Nothing other than" .)