Fused lead taking yonks to melt (9)

I believe the answer is:

ankylosed

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'fused' is the definition.
Although both the answer and definition are past participle verbs, I cannot understand how they can define each other.

'lead taking yonks to melt' is the wordplay.
'taking' says to put letters next to each other.
'to melt' indicates an anagram.
'lead'+'yonks'='leadyonks'
'leadyonks' anagrammed gives 'ANKYLOSED'.

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