Initially sees her undressed this close! (4)
I believe the answer is:
shut
'close' is the definition.
(I know that close can be written as shut)
'initially sees her undressed this' is the wordplay.
'initially' indicates taking the first letters.
The initial letters of 'sees her undressed this' is 'SHUT'.
(Other definitions for shut that I've seen before include "See 19" , "Closed" , "Draw to" , "Slam" , "not accepting visitors" .)