Make a note of the time perhaps (4)
I believe the answer is:
item
'make a note of' is the definition.
The definition and answer can be both related to thinking as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'time perhaps' is the wordplay.
'perhaps' is an anagram indicator.
'time' with letters rearranged gives 'ITEM'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for item that I've seen before include "Article, object" , "Piece of news: unit" , "two with a link" , "Detail (in a list)" , "Book-keeping entry" .)