Don't reveal some foolish ideas (4)
I believe the answer is:
hide
'don't' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's a link between them I don't understand?
'some foolish ideas' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'HIDE' is hidden within 'foolish ideas'.
'reveal' is the link.
Can you help me to learn more?
(Other definitions for hide that I've seen before include "Keep out of sight" , "Mammal's tough skin" , "Keep quiet" , "Animal retreat" , "Tanned skin of an animal" .)