For a semi-detached, shows potential (7)
I believe the answer is:
promise
'potential' is the definition.
(I've seen this before)
'for a semi-detached' is the wordplay.
I cannot quite understand how this works, but
'for' could be 'pro' (as in being 'pro' or in favour of something) and 'pro' is found in the answer.
an anagram of 'semi' is 'mise' which is present in the answer.
No letters remain.
This explanation may well be incorrect...
'shows' acts as a link.
Can you help me to learn more?
(Other definitions for promise that I've seen before include "Hopeful sign" , "Cause for hope" , "Guarantee" , "Verbal or other commitment of one person to another" , "Oath" .)