Take to be a clue (4)
I believe the answer is:
lead
I believe this is a triple definition!
'take' is the first definition.
(synonyms)
'to be' is the second definition.
(leading is a kind of being)
'a clue' is the third definition.
(e.g. in a police investigation)
(Other definitions for lead that I've seen before include "Top actor" , "Church windows include this" , "Live" , "Guide, direct" , "Guide the heavy metal" .)