Strange thing to see before autumn, even for poet (9)
I believe the answer is:
nightfall
'even for poet' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'strange thing to see before autumn' is the wordplay.
'strange' indicates an anagram.
'to see before' means one lot of letters go next to another.
'autumn' becomes 'fall' (synonyms).
'thing' is an anagram of 'night'.
'night'+'fall'='NIGHTFALL'
Can you help me to learn more?
(Other definitions for nightfall that I've seen before include "when visibility reduces" , "Arrival of darkness" , "after sunset" , "The onset of darkness" , "start of the dark time" .)