Strainer is returned by First Lady (5)
I believe the answer is:
sieve
'strainer' is the definition.
(sieve is a kind of strainer)
'is returned by first lady' is the wordplay.
'returned' is a reversal indicator.
'by' is a charade indicator (letters next to each other).
'first lady' becomes 'eve' (I've seen this before).
'is' written backwards gives 'si'.
'si'+'eve'='SIEVE'
(Other definitions for sieve that I've seen before include "Device for separating lumps" , "Eratosthenes' invention" , "Mesh used for straining or sifting" , "Screen, sift, strain" , "Utensil for straining or sifting food" .)