Spherical solid (3)
I believe the answer is:
orb
'spherical solid' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for orb that I've seen before include "Ceremonial globe carried by a monarch" , "Poetically eye" , "Part of royal regalia" , "Item of insignia" , "A poetic eye, bro" .)