Refer indirectly (6)
I believe the answer is:
allude
'refer indirectly' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for allude that I've seen before include "Refer (to) in passing" , "Refer to, speak of" , "Speak about in passing" , "Mention; imply" , "Make reference to in passing" .)