Native American trails in quarry — one's taken aback (10)
I believe the answer is:
indigenous
'native' is the definition.
(similar in meaning)
'american trails in quarry one's taken aback' is the wordplay.
'american' becomes 'us' (abbreviation for United States).
'trails' is a charade indicator (letters next to each other) (some letters follow or trail others).
'quarry' becomes 'dig' (quarry can mean to dig).
'taken aback' is a reversal indicator.
'one' written backwards gives 'eno'.
'in'+'dig'+'eno'='indigeno'
'us' put after 'indigeno' is 'INDIGENOUS'.
(Another definition for indigenous that I've seen is " Native".)