Plait rearranged around one girl's head? (7)
I believe the answer is:
pigtail
'head?' is the definition.
The definition and answer can be both body parts as well as being singular nouns.
Maybe there's an association between them I don't understand?
'plait rearranged around one girl's' is the wordplay.
'rearranged' indicates an anagram.
'around' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'girl' becomes 'g'.
'plait' is an anagram of 'ptail'.
'i'+'g'='ig'
'ptail' placed around 'ig' is 'PIGTAIL'.
(Other definitions for pigtail that I've seen before include "Schoolgirl's plait" , "Braid of hair" , "Plaited lock of hair" , "Long plait" , "Plaited hair style" .)