Seventh planet from the sun (6)
I believe the answer is:
uranus
'seventh planet from the sun' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for uranus that I've seen before include "Planet discovered by William Herschell in 1781" , "heavenly body" , "Giant planet" , "Planet discovered in 1781 by Herschel" , "Uses profane language" .)