For Alan to break out of a terrible rut is reasonable (7)
I believe the answer is:
natural
'is reasonable' is the definition.
(thesaurus)
'for alan to break out of' is the wordplay.
'for' becomes 'tur' (I can't justify this - if you can you should believe this answer much more).
'to break' is an anagram indicator.
'out of' means one lot of letters goes inside another (some letters on the outside of others).
'alan' with letters rearranged gives 'naal'.
'tur' placed inside 'naal' is 'NATURAL'.
'a terrible rut' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for natural that I've seen before include "Fuel from underground" , "Innate -- unprocessed" , "Additive-free" , "pure" , "Unsophisticated" .)