Spaniel barking at government leader? Good! (8)
I believe the answer is:
pleasing
'good' is the definition.
(similar in meaning)
'spaniel barking at government leader?' is the wordplay.
'barking' is an anagram indicator (UK slang for mad).
'at' means one lot of letters go next to another.
'leader?' indicates taking the first letters (I've seen 'leaders' mean this).
The first letter of 'government' is 'g'.
'spaniel' anagrammed gives 'pleasin'.
'pleasin'+'g'='PLEASING'
(Other definitions for pleasing that I've seen before include "Gratifying" , "Pleasurable; satisfying" , "making one happy" , "Delightful" , "Satisfying or appealing" .)