Spanish nobleman concealed criminal in gaol, oddly (7)
I believe the answer is:
hidalgo
'spanish nobleman' is the definition.
(I've seen this in another clue)
'concealed criminal in gaol oddly' is the wordplay.
I cannot quite understand how this works, but
'concealed' could be 'hid' ('hide' can be a synonym of 'conceal') and 'hid' is found in the answer.
an anagram of 'gaol' is 'algo' which is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for hidalgo that I've seen before include "foreign gentleman" , "Spanish fellow" , "Pachuca is capital of this Mexican state" , "Spanish aristocrat" , "Spanish nobleman" .)