Avoid first woman holding poster (5)
I believe the answer is:
evade
'avoid' is the definition.
(evading is a kind of avoiding)
'first woman holding poster' is the wordplay.
'first woman' becomes 'eve' (I've seen this before**).
'holding' indicates putting letters inside.
'poster' becomes 'ad'.
'eve' placed around 'ad' is 'EVADE'.
(Other definitions for evade that I've seen before include "Dodge or equivocate" , "Shun, escape" , "Escape (esp. by guile)" , "Keep away from" , "Manage to avoid" .)