Ring for the head, boy needing permit (7)
I believe the answer is:
Here is my best explanation:
'ring for the head' is the definition.
'boy needing permit' is the subsidiary indication.
'boy' becomes 'chap' (I've seen this before**).
'needing' says to put letters next to each other.
'permit' becomes 'let' ('let' can be a synonym of 'permit').
(Other definitions for chaplet that I've seen before include "top band?", "Circular garland for the head", "flower arrangement", "Little fellow", "Ornamental wreath worn on the head", "Garland or wreath for the head" and "Wreath for the head".)