Told to go in conversation with guide (5)
I believe the answer is:
scent
'with guide' is the definition.
The definition and answer can be both related to thinking as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'told to go in conversation' is the wordplay.
'told to go' becomes 'sent'.
'in conversation' shows a homophone (sound like).
'sent' is a homophone of 'SCENT'.
Can you help me to learn more?
(Other definitions for scent that I've seen before include "Fragrance" , "Distinctive odour" , "Get wind of" , "Pleasant smell" , "Number of clues" .)