Quite an odd arrangement – and quite an old thing (7)
I believe the answer is:
antique
'arrangement and quite an old thing' is the definition.
I can't judge whether this defines the answer.
'quite an odd' is the wordplay.
'odd' is an anagram indicator.
'quite'+'an'='quitean'
'quitean' is an anagram of 'ANTIQUE'.
Can you help me to learn more?
(Other definitions for antique that I've seen before include "Valuable due to age, like some furniture" , "Old-fashioned, outdated" , "Venerably old" , "Long-standing" , "(Something) valuable because of age and quality" .)