Field worker career's ruined by that woman (10)
I believe the answer is:
researcher
'field worker' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'career's ruined by that woman' is the wordplay.
'ruined' is an anagram indicator.
'by' says to put letters next to each other.
'that woman' becomes 'her' (pronoun for a woman).
'careers' is an anagram of 'researc'.
'researc'+'her'='RESEARCHER'
Can you help me to learn more?
(Other definitions for researcher that I've seen before include "Person investigating" , "I investigate" , "analyst" , "One seeks information" , "One investigating" .)