Egotist from South America thus raced back (9)
I believe the answer is:
narcissus
'egotist' is the definition.
(the mythical Narcissus was famously self-absorbed)
'south america thus raced back' is the wordplay.
'south america' becomes 'sus' (I can't justify this - if you can you should give a lot more credence to this answer).
'thus' becomes 'sic' ('thus' in Latin).
'raced' becomes 'ran' ('run' can be a synonym of 'race').
'back' says the letters should be written in reverse.
'sus'+'sic'+'ran'='sussicran'
'sussicran' written backwards gives 'NARCISSUS'.
'from' is the link.
(Other definitions for narcissus that I've seen before include "Garden flower - youth of Greek mythology" , "Flower like daffodil" , "Beautiful fellow" , "Legendary egotist" , "Mythical egotist" .)