Indefatigable essayist? (5)
I believe the answer is:
trier
'essayist?' is the definition.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for trier that I've seen before include "town in Germany" , "Persevering type" , "home for some Germans" , "One who doesn't give up - judge?" , "Persistent type" .)