Only second shout of approval in Seville (4)
I believe the answer is:
sole
'only' is the definition.
(I know that only can be written as sole)
'second shout of approval in seville' is the wordplay.
I cannot really see how this works, but
'second' could be 's' (common abbreviation) and 's' is found within the answer.
'shout' could be 'ole' (I've seen this in another clue) and 'ole' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sole that I've seen before include "Kind of fish - lose it" , "A lonely sort of flatfish" , "One and only; part of foot" , "A lone sort of fish - lose it" , "Fish - alone" .)