Unions somehow have to finish insinuations (10)
I believe the answer is:
innuendoes
'insinuations' is the definition.
('innuendo' can be a synonym of 'insinuation')
'unions somehow have to finish' is the wordplay.
I cannot really understand how this works, but
'finish' could be 'end' (come to an end) and 'end' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for innuendoes that I've seen before include "Suggestive remarks" , "insinuations" .)