Lab rebuilt round ruined manor? That's strange (8)
I believe the answer is:
abnormal
'strange' is the definition.
(I've seen this before)
'lab rebuilt round ruined manor?' is the wordplay.
'rebuilt' is an anagram indicator.
'round' indicates putting letters inside.
'ruined' indicates anagramming the letters.
'lab' is an anagram of 'abl'.
'manor' with letters rearranged gives 'norma'.
'abl' enclosing 'norma' is 'ABNORMAL'.
'that's' is the link.
(Other definitions for abnormal that I've seen before include "Deviating from the usual" , "Extraordinary" , "Anomalous" , "Peculiar, unnatural" , "Irregular" .)