Like ABBA? Like a turnip? (7)
I believe the answer is:
swedish
I believe this clue is a double definition.
'like abba?' is the first definition.
(I've seen this before)
'turnip?' is the second definition.
(swedish turnip is a kind of turnip)
'like a' acts as a link.
(Other definitions for swedish that I've seen before include "Soprano Jenny Lind, b. Stockholm 1798, d. Herefordshire 1887" , "like Bergman" , "Eg, native to Stockholm" , "from European country" , "A Scandinavian language" .)