Hint slyly (9)
I believe the answer is:
'hint slyly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for insinuate that I've seen before include "Imply about annuities" , "Subtly introduce" , "Suggest by indirect means" , "Annuities (anag.)" , "Intimate with annuities" .)