Unattractive leaders of union given little say, ultimately (4)
I believe the answer is:
ugly
'unattractive' is the definition.
('ugly' is associated in meaning with 'unattractive')
'leaders of union given little say ultimately' is the wordplay.
'leaders of' says to take the initial letters.
'ultimately' indicates one should take the final letters.
The initial letters of 'union given little' is 'ugl'.
The last letter of 'say' is 'y'.
'ugl'+'y'='UGLY'
(Other definitions for ugly that I've seen before include "Evil-looking" , "Repulsive in appearance" , "Unsightly, not pretty" , "Revolting" , "Grotesque" .)