Eccentric hobby is not polite (7)
I believe the answer is:
yobbish
'not polite' is the definition.
I can't judge whether this defines the answer.
'eccentric hobby is' is the wordplay.
'eccentric' indicates an anagram.
'hobby'+'is'='hobbyis'
'hobbyis' anagrammed gives 'YOBBISH'.
Can you help me to learn more?
(Other definitions for yobbish that I've seen before include "Rude, aggressive, noisy" , "Ill-bred" , "rudely aggressive" , "Like a lout" , "Behaving badly" .)