Italian family held back by Thai family (5)
I believe the answer is:
mafia
'italian family' is the definition.
The answer and definition can be both groups as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'held back by thai family' is the wordplay.
'back by' is a reversal indicator.
'held' indicates the answer is hidden within the clue.
'aifam' is hidden in the letters of 'thai family'.
'aifam' back-to-front is 'MAFIA'.
Can you help me to learn more?
(Other definitions for mafia that I've seen before include "organised criminals" , "Sicilian secret society" , "International crime organisation originating in Sicily" , "Secret criminal organisation" , "The Sicily mob" .)