Men let gannet free in mix-up (12)
I believe the answer is:
entanglement
'mix-up' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'men let gannet free' is the wordplay.
'free' indicates an anagram.
'men'+'let'+'gannet'='menletgannet'
'menletgannet' with letters rearranged gives 'ENTANGLEMENT'.
'in' is the link.
Can you help me to learn more?
(Other definitions for entanglement that I've seen before include "Confused state; perplexity" , "Ill-advised liaison" , "Imbroglio" , "A complication" .)