Strain is back with pioneering woman (5)
I believe the answer is:
sieve
'strain' is the definition.
(synonyms)
'is back with pioneering woman' is the wordplay.
'back' says the letters should be written backwards.
'with' means one lot of letters go next to another.
'pioneering woman' becomes 'Eve' (first woman in the Bible).
'is' reversed gives 'si'.
'si'+'eve'='SIEVE'
(Other definitions for sieve that I've seen before include "Straining device" , "Meshed kitchen utensil" , "Mesh used for straining or sifting" , "Eratosthenes' invention" , "Screen, sift, strain" .)