Country full of males in song (7)
I believe the answer is:
armenia
'country' is the definition.
(Armenia is a country)
'males in song' is the wordplay.
'males' becomes 'men' (man is a kind of male).
'in' means one lot of letters goes inside another.
'song' becomes 'aria' (piece of music in an opera).
'men' going into 'aria' is 'ARMENIA'.
'full of' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for armenia that I've seen before include "Landlocked country of southwest Asia" , "Former Russian republic, its capital Yerevan" , "Republic formerly in the USSR" , "South-west Asian country, capital Yerevan" , "Mountainous republic bordering Turkey" .)