At one time included, quoted in vain (9)
I believe the answer is:
conceited
'in vain' is the definition.
(I've seen this before)
'at one time included quoted' is the wordplay.
I cannot quite understand how this works, but
'at' could be 'on' (location) and 'on' is present in the answer.
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
'time' could be 't' (abbreviation) and 't' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for conceited that I've seen before include "Arrogant" , "Vain; narcissistic" , "Stuck-up" , "Swollen-headed" , "Excessively vain" .)