In the autumn boot out this (8)
I believe the answer is:
football
'this' is the definition.
The definition suggests a singular noun which matches the answer.
'in the autumn boot out' is the wordplay.
'in the' means one lot of letters goes inside another.
'autumn' becomes 'fall' (synonyms).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'boot' is an anagram of 'ootb'.
'fall' going around 'ootb' is 'FOOTBALL'.
Can you help me to learn more?
(Other definitions for football that I've seen before include "Lob aloft poorly for this game" , "Lob aloft (anag)" , "Loft a lob badly in this game" , "Strange ballot of the game" , "Team sport" .)