Study Hesiod's conclusion in French (3)
I believe the answer is:
den
'study' is the definition.
(term for a study or office)
'hesiod's conclusion in french' is the wordplay.
'conclusion' suggests the final letters.
'in french' becomes 'en' ('in' in French).
The last letter of 'hesiod' is 'd'.
'd'+'en'='DEN'
(Other definitions for den that I've seen before include "Miserable place" , "Room for work or play" , "Animal's lair or man's study" , "Hideaway" , "Hiding place" .)