Spherical hairdo (4)
I believe the answer is:
afro
'spherical hairdo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for afro that I've seen before include "Shock description" , "Of hair style, tightly curled and bushy" , "Tightly-curled 4 down" , "Hairstyle with tight curls" , "Type of hairstyle - from Africa" .)