Feel the absence of unmarried woman (4)
I believe the answer is:
miss
I believe this clue is a double definition.
'feel the absence of' is the first definition.
(I've seen this before)
'unmarried woman' is the second definition.
(I've seen this before)
(Other definitions for miss that I've seen before include "Fail to hear" , "Yearn for" , "maiden" , "Pine for - young lady" , "Suffer from the lack of" .)