Dress down (8)
This might be a double definition.
'dress' is the first definition.
(I know that dress can be written as preen)
'down' is the second definition.
The definition and answer can be both to do with contact as well as being verbs in their base form.
Maybe you can see a link between them that I don't see?
Can you help me to learn more?
(Other definitions for preen that I've seen before include "Groom with great care" , "(Of a bird) tidy and clean feathers" , "Arrange feathers" , "Dress or smooth, feathers say" , "Maintain" .)
'dress down' is the definition.
(chastising is a kind of dressing down)
This is all the clue.
(Other definitions for chastise that I've seen before include "Beat" , "Censure severely" , "Berate" , "Scold severely" , "Punished severely" .)