Unwilling to get an awful clutter outside tidied up (9)
I believe the answer is:
reluctant
'unwilling' is the definition.
(similar in meaning)
'an awful clutter outside tidied up' is the wordplay.
'an awful' is an anagram indicator.
'outside' says to hollow out the word (remove centre letters).
'tidied up' becomes 'ant' (I can't justify this - if you can you should give a lot more credence to this answer).
'clutter' with its middle taken out is 'cluter'.
'cluter' with letters rearranged gives 'reluct'.
'reluct'+'ant'='RELUCTANT'
'to get' acts as a link.
Can you help me to learn more?
(Other definitions for reluctant that I've seen before include "Kenneth Grahame's dragon was" , "Slow" , "Not wishing to" , "Loth" , "Indisposed" .)