Scottish dance that sounds authentic (4)
I believe the answer is:
reel
'scottish dance' is the definition.
(I've seen this before)
'sounds authentic' is the wordplay.
'sounds' indicates a 'sounds like' (homophone) clue.
'authentic' becomes 'real' (I've seen this before).
'real' is a homophone of 'REEL'.
'that' acts as a link.
(Other definitions for reel that I've seen before include "energetic dance" , "Film spool" , "Fishing rod attachment" , "Lively dance; bobbin" , "Folk dance" .)