Country's defender, 3 smothered in a bit of butter (7)
I believe the answer is:
patriot
'country's defender' is the definition.
'patriot' can be an answer for 'defender' (I have seen 'Defender of country' mean 'patriot' so perhaps 'defender' could also mean 'patriot'). I'm unsure of the 'country's' bit.
'3 smothered in a bit of butter' is the wordplay.
'3' becomes 'trio' (synonyms).
'smothered in' indicates putting letters inside (I've seen this in other clues).
'a bit of butter' becomes 'pat' (I've seen this in another clue).
'trio' going into 'pat' is 'PATRIOT'.
Can you help me to learn more?
(Other definitions for patriot that I've seen before include "A lover of fatherland" , "Country-lover" , "New England sportsman" , "One supporting country" , "Flag waver" .)