Record I obtained: about fifty troubled sites for mouthpieces (12)

I believe the answer is:

epiglottises

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'mouthpieces' is the definition.
Although both the answer and definition are plural nouns, I can't understand how they can define each other.

'record i obtained about fifty troubled sites' is the wordplay.
'record' becomes 'ep'.
'obtained' becomes 'got' ('get' can be a synonym of 'obtain').
'about' means one lot of letters goes inside another.
'fifty' becomes 'l' (roman numeral).
'troubled' is an anagram indicator.
'got' going around 'l' is 'glot'.
'sites' with letters rearranged gives 'tises'.
'ep'+'i'+'glot'+'tises'='EPIGLOTTISES'

'for' is the link.

Can you help me to learn more?

I've seen this clue in The Hindu.

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