Groups of families around Spanish river having shrill trumpets (8)
I believe the answer is:
'shrill trumpets' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps there's an association between them I don't understand?
'groups of families around spanish river' is the wordplay.
'groups of families' becomes 'clans' (I am not sure about this - if you are sure you should believe this answer much more).
'around' indicates putting letters inside.
'spanish river' becomes 'rio' (I've seen this in another clue).
'clans' going around 'rio' is 'CLARIONS'.
'having' acts as a link.
Can you help me to learn more?
(Another definition for clarions that I've seen is " Medieval brass instruments with clear shrill tone".)