Australian girl in a muddle following blood groups (10)
I believe the answer is:
aboriginal
'australian' is the definition.
(Aboriginal is an example)
'girl in a muddle following blood groups' is the wordplay.
'muddle' is an anagram indicator.
'following' says to put letters next to each other.
'blood groups' becomes 'abo' (I've seen this in another clue).
'girl'+'in'+'a'='girlina'
'girlina' is an anagram of 'riginal'.
'riginal' after 'abo' is 'ABORIGINAL'.
(Other definitions for aboriginal that I've seen before include "Native Australian; indigenous" , "native language" , "First inhabitant" , "Relating to native Australians" , "resident in Australia?" .)