Suggested to poke around cause (8)
I believe the answer is:
proposed
'suggested' is the definition.
('propose' can be a synonym of 'suggest')
'poke around cause' is the wordplay.
'poke' becomes 'prod' (synonyms).
'around' means one lot of letters goes inside another.
'cause' becomes 'pose' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'prod' enclosing 'pose' is 'PROPOSED'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for proposed that I've seen before include "Popped the question" , "Nominated, put forward for consideration" , "Moved" , "Offered for consideration - perhaps marriage" , "Intended (to do something)" .)