Eggs some Geordies sent back (3)
I believe the answer is:
roe
'eggs' is the definition.
(I've seen this in another clue)
'some geordies sent back' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'sent back' says the letters should be written backwards.
'eor' can be found hidden inside 'geordies'.
'eor' back-to-front is 'ROE'.
(Other definitions for roe that I've seen before include "Hoofed animal(s)" , "If hard, eggs" , "Mass of fish eggs" , "Food from fish" , "Swift runner" .)