Those at the forefront of satire often laugh at readers of The Sun (5)
I believe the answer is:
solar
'of the sun' is the definition.
(I've seen this before)
'those at the forefront of satire often laugh at readers' is the wordplay.
'those at the forefront of' indicates taking the first letters.
The initial letters of 'satire often laugh at readers' is 'SOLAR'.
(Other definitions for solar that I've seen before include "chamber in old house" , "Particular star's" , "Sort of power" , "of heavenly body" , "Relating to the sun" .)