I'd crept off around back of house that's rickety (8)
I believe the answer is:
decrepit
'that's rickety' is the definition.
(I've seen this in another clue)
'i'd crept off around back of house' is the wordplay.
'off' indicates an anagram.
'around' indicates putting letters inside.
'back of' suggests the final letters.
The final letter of 'house' is 'e'.
'id'+'crept'='idcrept'
'idcrept' with letters rearranged gives 'decrpit'.
'decrpit' enclosing 'e' is 'DECREPIT'.
(Other definitions for decrepit that I've seen before include "run down" , "Worn and broken down by use" , "Depicter in state of dilapidation" , "ruined by neglect" , "Impaired by age" .)